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Abstract

The addition of hard ceramic particles of nc-(Ti,Mo)C in carbon network into Ti matrix has been proved to be an efficient way to enhance their properties. The purpose of this work was to analyze the corrosion, tribological, mechanical and morphological effects of combining nc-(Ti,Mo)C/C with titanium metal, to create a unique composite via selective laser melting technique (SLM). Composites with different weight percentage (5, 10 and 20 wt %) of ceramic phase were produced. The samples of pure Ti and Ti-6Al-4V alloy were also tested, as a reference. These composites were examined for corrosion resistance in body fluid (artificial saliva solution). Moreover, the properties of titanium composites reinforced with nc-TiC powders were compared. It was stated that mechanical properties were significantly improved with increasing amount of nc-(Ti,Mo)C/C in Ti matrix. In terms of corrosion resistance, the composites showed worse properties compared to pure titanium and Ti-6Al-4V alloy, but better than TiC-reinforced composites.

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Authors and Affiliations

P. Figiel
A. Biedunkiewicz
W. Biedunkiewicz
D. Grzesiak
M. Pawlyta
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Abstract

In this study, the combined effect of Zr and Si on isothermal oxidation of Ti for 25 and 50 h at 820°C, which is the temperature related to exhaust valves operation, was investigated. Si addition into Ti-5mass%Zr alloy led to a distribution of silicide Ti5Si3 phase formed by a eutectic reaction. The Ti sample containing only Zr showed more retarded oxidation rate than Ti-6Al-4V, the most prevalent Ti alloy, at the same condition. However, while a simultaneous addition of Zr and Si resulted in greater increase of oxidation resistance. The oxide layer formed after the addition of Zr and Si comprised TiO2, ZrO2, and SiO2.

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Authors and Affiliations

S.-H. Ha
B.-H. Kim
Y.-O. Yoon
H.-K. Lim
S.K. Kim
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Abstract

This paper presents the effect of the addition of Ti to the zinc bath. Hot-Dip Galvanizing was carried out on a machined ductile cast iron substrate. The process was carried out at 550°C. Experimental baths A, B and C contained 0.01%, 0.05% and 0.1%Ti, respectively. Metallographic samples were prepared to reveal the microstructure of the coatings. Thickness measurements of the obtained coatings were carried out, and graphs of the approximate crystallization kinetics of the zinc coating were prepared. High-temperature galvanization carried out on the treated surface led to the release of graphite beads from the metal matrix and their diffusion into the coating. This phenomenon can have an adverse effect on the continuity of the coating and its adhesion to the substrate. Crystallization of the δ phase was observed in the coating, and at longer immersion times – a mixture of two-phase δ1 and η phases. With increasing Ti content in the bath, a deterioration in the casting properties of the bath was observed.
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Bibliography

[1] Kopyciński, D., Guzik, E. & Woźnica, H. (2006). The gradient structure zinc coating shaping at the surface of ductile cast iron. Archives of Foundry. 6(22), 278-285.
[2] Kania, H. & Liberski, P. (2012) Synergistic influence of Al, Ni, Bi and Sn addition to a zinc bath upon growth kinetics and the structure of coatings. Materials Science and Engineering. 35, 1-10. DOI: 10.1088/1757-899X/35/1/012004.
[3] Kopyciński, D., Guzik, E. & Szczęsny, A. (2014). The effect of the number of eutectic grains on coating growth during hot dip galvanising of ductile iron castings. Archives of Foundry Engineering. 14(1), 67-70. ISSN (1897-3310).
[4] Kania, H. & Liberski, P. (2014). The structure and growth kinetics of zinc coatings on link chains produced of the 23MnNiCrMo5-2 steel. Solid State Phenomena. 212, 145- 150. DOI:10.4028/www.scientific.net/SSP.212.145.
[5] Kopyciński, D., Guzik, E., Szczęsny, A. & Siekaniec, D. (2015). Growth kinetics of the protective coating during high- and low- temperature process of hot dip galvanizing of ductile iron castings. Archives of Foundry Engineering. 15(spec.2), 47-50. ISSN (1897-3310). (in Polish).
[6] Kopyciński, D. (2015). Sequence of formation of intermetallic phases in a zinc coating. Inżynieria Materiałowa. 5(207), 251-255 DOI 10.15199/28.2015.5.10. (in Polish).
[7] Di Cocco, V. (2012). Sn and Ti influences on intermetallic phases damage in hot dip galvanizing. Frattura ed Integrità Strutturale. 22, 31-38. DOI: 10.3221/IGF-ESIS.22.05.
[8] Kania, H. & Liberski, P. (2008). High-temperature galvanizing. Ochrona przed korozją. 10, 370-376. (in Polish).
[9] Kubaschewski O. (1982). Iron – Binary phase diagrams. Berlin, Springer-Verlag.
[10] Massalski, T.B. (1990). Binary alloy phase diagrams. ASM International.
[11] Burton, P.B., Perrot, P. (1993). Phase diagram of binary iron alloys. American Society for Metals, Metals Park, OH, 1993, 459-466.
[12] Mackowiak, J. & Short, N.R. (1979). Metallurgy of galvanized coating. International Metals Reviews, 1, 1-19.
[13] Schubert, P. & Schultz, W.D. (2001). Was sind „reactive” Stähle – zum Einfluss von Wasserstoff in Baustählen auf die Schichtbildung beim Feuerverzinken. Metall. 55(12), 743-748.
[14] Schramm, J. (1936). Das System Eisen-Zink. Zeitschrift für Metallkunde, 28, 203-207.
[15] Schramm, J. (1937). Über eine neue Phase im System Eisen – Zink. Zeitschrift für Metallkunde. 29, 222-225.
[16] Scheil, E. & Wurst, H. (1937). Über die Reactionen des Eisens mit flüssigem Zink. Zeitchrift für Metallkunde, 29, 225-228.
[17] Schramm, J. (1938). Röntgenographische Unterschung der Phasen und Phasen-granzen in den System des ZInks mit Eisen, Kobalt und Nickel. Zeitschrift für Metallkunde. 30, 122-130.
[18] Schramm J. (1938). Über die Wärmetönungen der Dreiphasenumsetzungen in den System des Zinks mit Nickel, Kobalt, Eisen und Mangan. Zeitschrift für Metallkunde. 30, 131-134.
[19] Ghoniem, M.A. & Löhberg, K. (1972). Über die bei der Feuerverzinkung entstehenden δ1p und δ1k Schichten. Metall. 26, 1026-1030.
[20] Bastin, G.F., Loo, F.J.J. & Rieck, G.D. (1974). A new compound in the iron zinc system. Zeitschrift für Metallkunde. 65, 656-660.
[21] Bastin, G. F., Loo, F.J.J. & Rieck, G.D. (1976). On the texture in the δ (Fe-Zn) layer formed during hot dip galvanizing. Zeitschrift für Metallkunde. 67, 694-698.
[22] Bastin, G.F., Loo, F.J.J. & Rieck, G. D. (1977). On the δ phase in the Fe-Zn system. Zeitschrift für Metallkunde. 68, 359-361.
[23] Gelliings. P.J., Bree. E.W. & Gierman, G. (1979). Synthesis and characterization of homogoneous intermetallic Fe-Zn coumpounds (part I, the δ1 phase). Zeitschrift für Metallkunde. 70, 312-314,
[24] Gelliings, P.J., Bree, E.W. & Gierman, G. (1979). Synthesis and characterization of homogoneous intermetallic Fe-Zn coumpounds (part II: the ζ phase). Zeitschrift für Metallkunde. 70, 315-317.
[25] Gelliings, P.J., Gierman, G., Koster, D. & Kuit, J. (1980). Synthesis and characterization of homogoneous intermetallic Fe-Zn coumpounds (part III: Phase diagram). Zeitschrift für Metallkunde. 71, 70-75.
[26] Gelliings, P.J., Koster, D., Kuit, J. & Fransen, T. (1980). Synthesis and characterization of homogoneous intermetallic Fe-Zn coumpounds (part IV: thermodynamic properties). Zeitschrift für Metallkunde. 71, 150-154.
[27] Bohran-Tavakoli, A. (1984). Formation and growth of the δ1 phase in the Fe-Zn system. Part II. Zeitschrift für Metallkunde. 75, 350-355.
[28] Bohran-Tavakoli, A. (1984). On the formation and growth of the δ1 phase in the Fe-Zn system. Part II. Zeitschrift für Metallkunde. 75, 436-439.
[29] Grant, R.G., Cook, P.S. & Cook, D.C. (1995). Preparation and chemical analysys of high purity iron-zinc alloys. Journal Mater. Research. 10, 2454-2462.
[30] Liu, Z.T., Boisson, M. & Uwakweh, O.N.C. (1996). Kinetics of phase evolution of Zn-Fe intermetallics. Metallurgical and Materials Transactions. 27 A, 2904-2910.
[31] Bastin, G.F. & Loo, F.J. (1978). On the texture in the ζ(Fe Zn) layer formed during hot dip galvanizing system. Zeitschrift für Metallkunde. 69, 540-545.
[32] Hong, M. N. & Saka, H. (1997). Transmition electron microscopy of the iron-zinc δ1 intermetallic phase. Scripta Materialia. 36, 1423-1426.
[33] Hong, M.N. & Saka, H. (1997). Plasticity and grain boundry structure of the δ1p and δ1k intermetallic phase in the Fe-Zn system. Acta Metallurgica. 45, 4225-4230.
[34] Reumont, G., Perrot, P., Fiorani, J.M. & Hertz, J. (2000). Thermodynamic evaluation of the Fe-Zn system. Journal of Phase Equilibria. 21, 371-378.
[35] Mita, K., Ikeda, T., Maeda, M. (2000). Phase diagram study of Fe-Zn intermetallics. Journal of Phase Equilibria. 23, 1808-1815.
[36] Su, X., Tang, N.Y. & Toguri, J.M. (2001). Thermodynamic evaluation of the Fe-Zn system. Journal of Alloys and Compounds. 325, 129-136.
[37] Jędrzejczyk, D. & Hajduga, M. (2011). Effect of the surface oxidation on the hot-dip zinc galvanizing of cast iron. Archives of Metallurgy and Materials. 56(3), 839-849. https://doi.org/10.2478/v10172-011-0093-x.
[38] Jędrzejczyk. D. (2010). The influence of high-temperature treatment of cast iron on the structure of the surface layer formed as a result of hot-dip galvanizing. Ochrona przed Korozją. 2, 46-48.
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Authors and Affiliations

Karolina Bracka-Kęsek
1
ORCID: ORCID
Andrzej Szczęsny
1
ORCID: ORCID
Dariusz Kopyciński
1
ORCID: ORCID
Edward Guzik
1
ORCID: ORCID

  1. AGH University of Science and Technology, Department of Foundry Engineering, Al. Mickiewicza 30, 30-059 Kraków, Poland
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Abstract

To investigate the impact of various Al-Ti-B grain-refiners on solidification and grain-refining performance, a wrought aluminium alloy AA6182 was used. Three different grain-refiners from different manufacturers were used to establish the efficiency, i.e. contact time before casting, on the primary solidification and grain formation size. The primary solidification of α-Al grains at inoculation was observed by using thermal analysis (TA). Differential scanning calorimetry (DSC) was used in order to analyze the quality of various grain-refiners. The size of the primary grains was analyzed using optical microscopy (OM). Scanning electron microscopy (SEM) was used to estimate the size and distribution of Al3Ti and TiB2 particles in various grain-refiners and to establish the best efficiency of the investigated grain-refiners.

Within 1-4 min of inoculation the smallest fine equiaxed grains were achieved when either one of the investigated grain-refiners was added. It was established, that grain-refiner A contains higher content of impurities which do not melt in the experimental temperature range made by DSC method. The most pure grain-refiner turned out to be grain-refiner B, in which the most optimal number of TiB2 particles and particle size distribution was found.

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Authors and Affiliations

M. Vončina
J. Medved
L. Jerina
I. Paulin
P. Cvahte
M. Steinacher
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Abstract

In this study, BaFe12-2xCoxTixO19 (X : 0 to 2.0, 0.2) powders were synthesized by sol-gel process. TG-DTA, XRD, SEM, VSM, and Network analyzer were measured in order to influence easy magnetization axis change on the wave absorption frequency range change. The easy magnetization axis change of the annealed powder at 900°C and 1200°C was confirmed by the coercive force decreased 4,800 and 3,870 Oe to 260 and 269 Oe, respectively, at the substitution ratio of 0.8 and 1.0. And it was confirmed that the change of the easy magnetization axis affected the change of the wave absorption frequency. The wave absorption frequency of substituted Barium Ferrite was less than 10 GHz range after the easy magnetization axis of Barium ferrite changed to a-b plan direction. It was confirmed the BaFe12-2xCoxTixO19(x = 0.8 to 1.6) was synthesized by the sol-gel process and it was annealed at 900°C and 1200°C, which could be used as a wave absorber in the X-band region of 10 GHz less.

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Authors and Affiliations

Su-Won Yang
Jeong-Gon Kim
Kwang-Pil Jeong
Han-Ul Shim
Seong-Il Cho
Min-Young Kim
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Abstract

Nanostructured, biocompatible, TiC/Ti Supersonic Cold Gas Sprayed coatings were deposited onto a Ti6Al4V alloy and their microstructure, wear resistance and hardness were investigated. The starting nanostructured powder, containing a varied mixture of Ti and TiC particles, was produced by high energy ball milling. Scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction were used for structural and chemical analyses of powder particles and coatings. Coatings, 250-350 μm thick, preserving the nanostructure and chemical powder composition, with low porosity and relatively high hardness (~850 HV), were obtained. These nanostructured TiC/Ti coatings exhibited better tribological properties than commonly used biomedical benchmark materials, due to an appropriate balance of hard and soft nano-phases.
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Authors and Affiliations

J. Kusiński
S. Kac
K. Kowalski
S. Dosta
E.P. Georgiou
J. Garcia-Forgas
P. Matteazzi
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Abstract

The current study were performed in order to assess the fabrication possibility of the metal-ceramic composites based on nanocrystalline substrates. The influence of the variable time of the high energy ball-milling (10, 30 and 50 h) on the structure, pores morphology and microhardness of Ti/ZrO2 and Ti/Al2O3 compositions was studied. The X-ray diffraction analysis confirmed the composite formation for all milling times and sintering in the case of Ti/ZrO2 system. Decomposition of substrates during milling process of Ti/Al2O3 system was also observed. Additionally, the changes of lattice parameter as a function of milling time were studied. The morphology of powders and the microstructure of the sintered samples were observed by scanning electron microscopy (SEM). Also, analysis of microhardness and pores structure were performed.

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Authors and Affiliations

G. Dercz
I. Matuła
W. Gurdziel
N. Kuczera
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Abstract

This paper summarizes the contribution of Polish scientific units to the development of the Global Geodetic Observing System (GGOS) in recent years. We discuss the issues related to the integration of space geodetic techniques and co-location in space onboard Global Navigation Satellites Systems (GNSS) and Low Earth Orbiters (LEO), as well as perspectives introduced by the new European Space Agency’s (ESA) mission GENESIS. We summarize recent developments in terms of the European Galileo system and its contribution to satellite geodesy and general relativity, as well as ESA’s recent initiative – Moonlight to establish a satellite navigation and communication system for the Moon. Recent progress in troposphere delay modeling in Satellite Laser Ranging (SLR) allowed for better handling of systematic errors in SLR, such as range biases and tropospheric biases. We discuss enhanced tropospheric delay models for SLR based on numerical weather models with empirical corrections, which improve the consistency between space geodetic parameters derived using different techniques, such as SLR, GNSS, and Very Long Baseline Interferometry (VLBI). Finally, we review recent progress in the development of Polish GGOS scientific infrastructure in the framework of the European Plate Observing System project EPOS-PL¸.
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Authors and Affiliations

Krzysztof Sosnica
1
ORCID: ORCID
Radoslaw Zajdel
1
ORCID: ORCID
Jaroslaw Bosy
1
ORCID: ORCID

  1. Wroclaw University of Environmental and Life Science, Wroclaw, Poland
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Abstract

Metal-intermetallic layered (MIL) composites attract considerable attention due to their remarkable structural and ballistic performance. This study aimed to develop a Ti/Al-based multilayered MIL material by adding ceramic powders, since they can improve the composite’s impact resistance. To this end, an experiment was conducted which a stack of alternating Ti and Al sheets bonded by hot pressing; Ti/Al multilayers containing additional layers of Al2O3 and SiC powders were also produced. The samples obtained were examined using electron microscopy techniques. The clads’ mechanical properties were investigated using a Charpy hammer. In the reaction zone, only one intermetallic phase occurred: the Al3Ti phase. The model with an additional Al2O3 layer showed the highest impact energy. None of the Ti/Al clads broke during the Charpy impact test, a result proving their high ductility.
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Bibliography

[1] I.A. Bataev, A.A. Bataev, V.I. Mali, D.V. Pavliukova, Structural and mechanical properties of metallic-intermetallic laminate composites produced by explosive welding and annealing, Mater. Design 35, 225-234 (2012). DOI: https://doi.org/10.1016/j.matdes.2011.09.030
[2] F. Foadian, M. Soltanieh, M. Adeli, M. Etminanbakhsh, A Study on the Formation of Intermetallics During the Heat Treatment of Explosively Welded Al-Ti Mulitlayers, Metall. Mater. Trans. A 45A, 1823 (2014). DOI: https://doi.org/10.1007/s11661-013-2144-6
[3] H. Paul, Ł. Maj, M. Prażmowski, A. Gałka, M. Miszczyk, P. Petrzak, Microstructure and mechanical properties of multilayered Al/Ti composites produced by explosive welding, Procedia Manufacturing 15, 1391-1398 (2018). DOI: https://doi.org/10.1016/j.promfg.2018.07.343
[4] D.M. Fronczek, R. Chulist, Z. Szulc, J. Wojewoda-Budka, Growth kinetics of TiAl3 phase in annealed Al/Ti/Al explosively welded clads, Mater. Lett. 198, 160-163 (2017). DOI: https://doi.org/10.1016/j.matlet.2017.04.025
[5] F. Kong, Y. Chen, D. Zhang, Interfacial microstructure and shear strength of Ti-6Al-4V/TiAl laminate composite sheet fabricated by hot packed rolling, Mater. Design 32, 3167-3172 (2011). DOI: https://doi.org/10.1016/j.matdes.2011.02.052
[6] H. Xiao, Z. Qi, C. Yu, C. Xu, Preparation and properties for Ti/ Al clad plates generated by differential temperature rolling, J. Mater. Process. Tech. 249, 285-290 (2017). DOI: https://doi.org/10.1016/j.jmatprotec.2017.06.013
[7] M. Fan, Z. Luo, Z. Fu, X. Guo, J. Tao, Vacuum hot pressing and fatigue behaviors of Ti/Al laminate composites, Vacuum 154, 101- 109 (2018). DOI: https://doi.org/10.1016/j.vacuum.2018.04.047
[8] L. Qin, M. Fan, X. Guo, J. Tao, Plastic deformation behaviors of Ti-Al laminated composite fabricated by vacuum hot-pressing, Vacuum 155, 96-107 (2018). DOI: https://doi.org/10.1016/j.vacuum.2018.05.021
[9] J . Li, K.H. Wang, K. Zhang L.L. Kang, H. Liang, Mechanism of interfacial reaction between Ti and Al-ceramic, Mater. Design 105, 223-233 (2016). DOI: https://doi.org/10.1016/j.matdes.2016.05.073
[10] G .H.S.F.L. Carvalho, I. Galvão, R. Mendes, R.M. Leal, A. Loureiro, Explosive welding of aluminium to stainless steel, J. Mat. Process. Tech. 262, 340-349 (2018). DOI: https://doi.org/10.1016/j.jmatprotec.2018.06.042
[11] I. D. Zakharenko, Critical conditions in detonation welding, Fizika Goreniya i Vzryva 8 (3), 422-427 (1972).
[12] M. Tayyebi, D. Rahmatabadi, M. Adhami, R. Hashemi, Influence of AR B technique on the microstructural, mechanical and fracture properties of the multilayered Al1050/Al5052 composite reinforced by SiC particles, J. Mater. Res. Tech. 8 (5), 4287-4301 (2019). DOI: https://doi.org/10.1016/j.jmrt.2019.07.039
[13] M.N. Yuan, Lili Li, Zh J. Wang, Study of the microstructure modulation and phase formation of Ti-Al3Ti laminated composites, Vacuum 157, 481-486 (2018). DOI: https://doi.org/10.1016/j.vacuum.2018.09.002
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Authors and Affiliations

W. Kowalski
1
ORCID: ORCID
H. Paul
1
ORCID: ORCID
P. Petrzak
1
ORCID: ORCID
Ł. Maj
1
ORCID: ORCID
I. Mania
1
ORCID: ORCID
M. Faryna
1
ORCID: ORCID

  1. Institute of Metallurgy and Materials Science , Polish Academy of Sciences , 25 Reymonta Str., 30-059 Kraków, Poland
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Abstract

Ferrotitanium can be produced as a method of recycling Ti scraps. The eutectic composition of ferrotitanium, Fe29.5Ti70.5, can be obtained as a nanocrystalline phase due to relatively low melting point. Fe29.5Ti70.5 in which FeTi and β-Ti form a lamellar structure have high strength but low strain. To improve this, impurities were removed through hydrogen plasma arc melting (HPAM) and annealed. HPAM can remove substitutional/interstitial solid solutions. As a result, from 6733 ppm to 4573 ppm of initial impurities were removed by HPAM process. In addition, the strain was improved by spheroidizing and coarsening the lamellar structure through annealing. The effect of impurities removed through HPAM on the Young’s modulus, yield strength, and strain was observed.
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Bibliography

[1] J.M. Park, D.H. Kim, K.B. Kim, N. Mattern, J. Eckert, J. Mater. Res. 26, 365 (2011).
[2] M. Dao, L. Lu, R. Asaro, J.T. M. De Hosson, E. Ma, Acta Mater. 55, 4041 (2007).
[3] K . Bensadok, S. Benammar, F. Lapicque, G. Nezzal, J. Hazard. Mater. 152, 423 (2008).
[4] J. Chae, J.-M. Oh, S. Yoo, J.-W. Lim, Korean J. Met. Mater. 57, 569 (2019).
[5] J.-M. Oh, K.-M. Roh, J.-W. Lim, J. Hydrog. Energy 41, 23033 (2016).
[6] J.-M. Oh, B.-K. Lee, C.-Y. Suh, J.-W. Lim, J. Alloy. Compd. 574, 1 (2013).
[7] J.-W. Lim, G.-S. Choi, K. Mimura, M. Isshiki, Met. Mater. Int. 14, 539 (2008).
[8] K . Mimura, S.-W. Lee, M. Ishiki, J. Alloy. Compd. 211, 267 (1995).
[9] M.W. Chase Jr, W. Malcom, NIST-JANAF Thermochemical Table, 4th ed, J. Phys. Chem. Ref. Deta, Mohograph 9, 154, 1537, 1759, 1776 (1995).
[10] J. Das, K. Kim, F. Baier, W. Lӧser, J. Eckert, Appl. Phys. Lett. 87, 161907 (2005).
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Authors and Affiliations

Suhwan Yoo
1
Jung-Min Oh
1
Jaeyeol Yang
2
Jaesik Yoon
2
Jae-Won Lim
1

  1. Jeonbuk National University, Division of Advanced Materials Engineering, College of Engineering, Jeonju 54896, Republic of Korea
  2. Korea Basic Science Institute, Division of Earth and Environmental Science, Cheongju 28119, Republic of Korea
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Abstract

A series of Al-5Ti-1B master alloys were obtained via fluoride salt process by holding them between 780°C and 880°C for 10-90 min. The influence of holding temperature and time during preparation on the microstructure and its refining performance were investigated by X-ray diffractometer, optical microscopy and scanning electron microscopy equ ipped with energy dispersive X-ray spectroscopy. The results indicated both the morphology and the distribution of TiB2 and Al3Ti were seriously affected by holding conditions. Inadequate TiB2 particles were generated when holding time was short. However, Fe-containing impurity particles that aggregated along the matrix grain boundaries were found after the prolonged holding time. The refining and microhardness test results revealed that Al -5Ti-1B, the one held at 820°C for 30 min showed the optimum refining efficiency on Al-Cu alloy.
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Authors and Affiliations

Y. Huang
H. Shao
Z. Xiao
X. Ren
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Abstract

The paper presents the results of research studies involving the ceramic-metal tool materials with the deposited nitride coatings on the basis of aluminium, titanium and silicon. The cathodic arc evaporation with lateral rotating cathodes method was used for deposition of nanocrystalline, wear resistant nitride coatings – AlTiSiN type. Structural examinations are presented of the applied coatings and their support material made on the scanning electron microscope (SEM) and the scanning/transmission electron microscope (STEM). Chemical composition analysis as a function of the distance from the specimen surface, the so-called profile analysis, were carried out also. The structural analysis confirms that deposited multilayer coatings have dense microstructure without any visible porosity and delamination. It was found that the investigated coatings have nanocrystalline structure and consisting of fine crystallites even less than 6nm. Lattice deformations and numerous structural defects were also observed in the nanolayers. Depositing the AlTiSiN coatings results in the significant hardness increase within the range of 2252 ±256 to 2908 ±295 HV0.01.
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Authors and Affiliations

A.E. Tomiczek
K. Gołombek
K. Matus
D. Pakuła
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Abstract

Modified Bohm’s formalism was applied to solve the problem of abstruse layer depth profiles measured by the Auger electron spectroscopy technique in real physical systems. The desorbed carbon/passive layer on an NiTi substrate and the adsorbed oxygen/ surface of an NiTi alloy were studied. It was shown that the abstruse layer profiles can be converted to real layer structures using the modified Bohm’s theory, where the quantum potential is due to the Auger electron effect. It is also pointed out that the stationary probability density predicts the multilayer structures of the abstruse depth profiles that are caused by the carbon desorption and oxygen adsorption processes. The criterion for a kind of break or “cut” between the physical and unphysical multilayer systems was found. We conclude with the statement that the physics can also be characterised by the abstruse measurement and modified Bohm’s formalism.

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Authors and Affiliations

E. Rówiński
M. Pietruszka
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Abstract

In the present investigation, the morphology of Ti inclusions in high strength tire cord steel was investigated and their precipitation behavior was discussed using a precipitation and growth model. The results show that Ti inclusions mainly exist in the form of TiN. The two-dimensional characterization of Ti inclusions is square-like with sharp edges and corners, while its three-dimensional shape exhibits a cubic or rectangular-prism morphology. The Ti inclusions do not precipitate when the solid fraction of tire cord during solidification is less than 0.987, and their final radius is closely related to the cooling rate and initial concentration product. The higher the cooling speed, the smaller the final radius, when the cooling speed is constant, the final radius of Ti inclusions is mainly determined by the initial concentration product, w[N]0×w[Ti]0. In order to retard the precipitation and growth of Ti inclusions in tire cord steel, the cooling rate and initial concentration product can be taken into consideration.

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Authors and Affiliations

Jialiu Lei
Dongnan Zhao
Yongjun Fu
Xianfeng Xu
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Abstract

Refinement is one of the most energy consuming technological process, aimed at obtaining mineral raw materials of the proper grain size.

Cast structural elements such as jaws or hammers in crushing machines operate under conditions of an intensive wear. The data indicate

that 80 % of failures of machines and devices is caused by wearing of rubbing surfaces. This problem became the subject of several

scientific and industrial investigations carried out in the whole world in order to produce materials ultra- wear resistant. Methods allowing

to obtain wear resistant composite castings are discussed in the hereby paper. Within the performed research microstructures of the

produced composite zones were presented and the comparative analysis with regard to mechanical and functional properties of local

composite reinforcements in relation to the commercial alloys of increased wear resistance was performed. The results show almost twenty

five times increase in wear resistance compared to manganese cast steel containing 18 % Mn.

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Authors and Affiliations

E. Olejnik
T. Tokarski
B. Grabowska
Ł. Szymański
P. Kurtyka
W. Maziarz
P. Czapla
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Abstract

This paper presents the study of microstructure and properties of 8 mol% yttrium stabilized zirconia coating fabricated by Plasma Spray Physical Vapor Deposition technique on commercial pure titanium. The coating was characterized by X-ray diffraction, high resolution scanning electron microscope, profilometer, nanoindentation and nanomachining tests. The X-ray phase analysis exhibit the tetragonal Zr0.935Y0.065O1.968, TiO and α-Ti phases. The Rietveld refinement technique were indicated the changes of crystal structure of the produced coatings. The characteristic structure of columns were observed in High Resolutions Scanning Electron Microscopy. Moreover, the obtained coating had various development of surfaces, thickness was equal to 3.1(1) µm and roughness 0.40(7) µm. Furthermore, the production coatings did not show microcracks, delamination and crumbing. The performed experiment encourages carried out us to tests for osseointegration.

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Authors and Affiliations

J. Barczyk
G. Dercz
I. Matuła
M. Góral
J. Maszybrocka
D. Bochenek
W. Gurdziel
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Abstract

The subject of the paper is structural stability of the Zn-26 wt.% Al binary alloys doped with 2.2 wt.% Cu or 1.6 wt.% Ti addition. The structural stability of Zn-Al alloys with increased Al content is connected with stability of solid solution of zinc in aluminium α', which is the main component of these alloys microstructure. Such a solution undergoes phase transformations which are accompanied, among others, by changes in dimensions and strength properties. The structural stability of the ZnAL26Cu2.2 and ZnAl26Ti1.6 alloys was investigated using XRD examinations during long term natural ageing after casting, as well as during long term natural ageing after super-saturation and quenching. On the basis of the performed examinations it was stated that small Ti addition to the binary ZnAl25 alloy, apart from structure refinement, accelerates decomposition of the primary α' phase giving stable structure in a shorter period of time in comparison with the alloy without Ti addition. Addition of Ti in amount of 1.6 wt.%, totally replacing Cu, allows obtaining stable structure and dimensions and allows avoiding structural instability caused by the metastable ε−CuZn4 phase present in the ZnAl26Cu2.2 alloy.

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Authors and Affiliations

W. Krajewski
P. Zak
J. Orava
A. Greer
P. Krajewski
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Abstract

This study was carried out to evaluate the aspect of microstructure and mechanical property development on additive manufactured pure Ti at elevated heat-input. For this work, pure Ti powder (commercial purity, grade 1) was selected, and selective laser melting was conducted from 0.5 to 1.4 J/mm. As a result, increase in heat-input led to the significant grain growth form 4 μm to 12 μm, accompanying with the change of grain shape, correctly widmanstätten structured grains. In addition, Vickers microhardness was notably increased from 228 Hv to 358 Hv in accordance with elevated heat-input, which was attributed to the increased concentration of oxygen and nitrogen mainly occurred during selected laser melting process.

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Authors and Affiliations

Dong-Jin Kim
Hyung-Giun Kim
Ji-Sun Kim
Kuk-Hyun Song
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Abstract

Multilayered composites based on light metals are promising materials in many applications. In the present work the 15-layered clad, composed of alternately stacked of Ti(Gr.1) and AA1050-H24 alloy sheets of 1 mm thick has been investigated with respect to determination of the kinetic of the Al3Ti phase growth. The defect-free multilayered composite was successfully formed by explosive welding technology. Then EXW samples were modified via annealing at the temperature of 600oC in closed die under pressure of 44 MPa for various times ranged between 1 and 10 h. Transmission and Scanning Electron Microscopy examinations were conducted in order to study the kinetic of the elements migration across the interfaces between the layers of the Al/Ti composite. The macro-scale observations of samples after EXW revealed that wavy interfaces were always formed in layers near the explosive charge. The increase of the distance from the top surface leads to flattening of the interface with very thin reaction layer between Al and Ti sheets. During annealing the kinetic of the Al3Ti phase growth is similar near all interfaces and coincides with data from other works. It was found that despite the loading after 10 h of annealing still only small part of Al-sheets undergoes dissolution and the width of the reaction layer does not exceed 5-8 µm.

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Authors and Affiliations

P. Petrzak
ORCID: ORCID
I. Mania
ORCID: ORCID
H. Paul
ORCID: ORCID
Ł. Maj
ORCID: ORCID
A. Gałka
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Abstract

The low adherence of diamond-like carbon (DLC) films on titanium (Ti) alloys can be improved by using interlayer coatings. In this study, DLC (a-C:H) films were deposited using radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD), and a TiCN interlayer was applied between the extra low interstitial (ELI) grade of Ti-6Al-4V alloy and a-C:H film. The characteristics of the a-C:H-coated Ti-6Al-4V ELI alloy were investigated using field emission scanning electron microscopy, Vickers hardness, and scratch and wear tests. The DLC (a-C:H) films deposited by rf-PECVD had a thickness of 1.7 µm, and the TiCN interlayer had a thickness of 1.1 µm. Vickers hardness of the DLC (a-C:H) films were increased as a result of the influence of the TiCN interlayer. The resulting friction coefficient of the a-C:H-coated Ti-6Al-4V with the TiCN interlayer had an extremely low value of 0.07.

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Authors and Affiliations

Kwangmin Lee
ORCID: ORCID
Seokil Kang
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Abstract

The lack of room-temperature ductility of high-strength TiAl-based alloys called for complicated high temperature processing limiting their application areas. Introduction of additive manufacturing (AM) methods allowed to circumvent this disadvantage, but entailed microstructure refinement affecting, among the others, their oxidation resistance. The dry-air high temperature oxidation processing of TiAl-based alloys is relatively well covered for coarse grained materials, but to what extent the TiAl alloys are affected by the changes caused by the AM remains to be found out. Additionally, the role of nitrogen during these processes was to large extent omitted in previous works. Within the present experiment, the mould cast (MC) and the electron beam melted (EBM) Ti-48Al-2Nb-0.7Cr-0.3Si (at. %) RNT650 alloys were dry-air oxidized at 650°C for 1000 h. The TEM/EDS investigations allowed to confirm that the scale formed during such treatment consists of the layers occupied predominantly by TiO2+Al2O3/TiO2/Al2O3 sequence. Additionally, it was shown that N diffuses to the sub-scale and reacts with the substrate forming two distinct discontinuous sub-layers of α2-Ti3Al(N) and TiN. The scale over EBM was noticeably less porous and nitrogen penetration of the substrate was more extensive, while the MC showed higher susceptibility to local sub-scale oxidation.
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Authors and Affiliations

J. Morgiel
1
ORCID: ORCID
T. Dudziak
2
ORCID: ORCID
L. Maj
1
ORCID: ORCID
A. Kirchner
3
M. Pomorska
1
ORCID: ORCID
B. Klöden
3
T. Weissgärber
3
D. Toboła
2
ORCID: ORCID

  1. Polish Academy of Science, Institute of Metallurgy and Materials Science, 25 Reymonta Str., 30-059-Kraków, Poland
  2. Łukasiewicz Research Network, Kraków Institute of Technology, 73 Zakopianska Str, 30-418 Kraków, Poland
  3. Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung IFAM, Institutsteil Dresden Winterbergstrasse 28, 01277 Dresden, Germany
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Abstract

The purpose of the present study was to extract high added value titanium from Ti-doped Seaside Magnetite Concentrated (Ti-SMC), which has a high potential reserve for Ti-Fe with 4–6% Ti, 50–52% F e, 1–2% A l, and 1–2% Mg content by applying innovative, economical, environmentally friendly methods. A gitaion HCl leaching was applied to the Ti-SMC sample at different leaching temperatures (25–50–75–90°C), at acid concentrations (8–10–12 N ), and leaching times (30–60– –120–240 min) in atmospheric conditions. A fter the leaching experiments under the indicated conditions, the optimization of the leaching experiments was determined with Ti% recovery that dissoluted by elemental analysis, and the titanium recovery values reached the maximum value with increased leaching time at 50°C and 10 N HCl acid concentration; and 65% Ti was recovered in 30 minutes, 67% in 60 minutes, 74% in 120 minutes, and 82% Ti in 240 minutes. F or Ti-SMC, leaching was carried out at 50°C leaching temperature and at 10 N acid concentration for 480 minutes, and a 92% Ti extraction value was achieved. A ccording to the extraction results of all leaching experiments, the leaching temperature of 50°C, the acid concentration of 10 N , and the leaching time of 480 minutes were determined as the optimum conditions. In this study, it was emphasized that this resource is a potential reserve, which has not been used as a source before, with 92% Ti extraction with atmospheric acid leaching, which is an environmentally friendly method, consuming less energy than Ti-SMC, which is difficult and expensive to extract with traditional methods.
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Authors and Affiliations

Elif Uzun Kart
1
ORCID: ORCID
Mümin Kırman
1
ORCID: ORCID

  1. Marmara University, İstanbul, Turkey
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Abstract

In this paper an analysis of the surface properties of (Ti,Pd,Eu)Ox thin films prepared by magnetron sputtering has been described. In particular, the results of composition and structure investigations were studied in relation to the surface state and optical properties. It was found that (Ti,Pd,Eu)Ox film was nanocrystalline and had a rutile structure. The average crystallites size was equal to 7.8 nm. Films were homogeneous and had densely packed grains. Investigation of the surface properties by XPS showed that titanium was present at 4+ state (in the TiO2form), palladium occurred as PdO2(also at 4+ state), while europium was in Eu2O3form (at 3+ state). In comparison with the unmodiffied TiO2, the coating with Pd and Eu additives had a rather high transparency (approx. 47%) in the visible light range, its optical absorption edge was shifted towards into the longer wavelengths (from 345 nm to 452 nm), and the width of optical energy gap Egopt was nearly twice lower (1.82 eV). Besides, the resistivity of (Ti,Pd,Eu)Ox at room temperature was 1×103 Wcm. In the case of the film as-deposited on Si substrate (p-type) the generation of photocurrent as a response to light beam excitation (λexc = 527 nm) was observed.

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Authors and Affiliations

D. Wojcieszak
D. Kaczmarek
J. Domaradzki

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