Widely used in the power and mining industry, cast Hadfield steel is resistant to wear, but only when operating under impact loads.
Components made from this alloy exposed to the effect of abrasion under load-free conditions are known to suffer rapid and premature
wear. To increase the abrasion resistance of cast high-manganese steel under the conditions where no dynamic loads are operating, primary
titanium carbides are formed in the process of cast steel melting, to obtain in the alloy after solidification and heat treatment, the
microstructure composed of very hard primary carbides uniformly distributed in the austenitic matrix of a hardness superior to the
hardness of common cast Hadfield steel. Hard titanium carbides ultimately improve the wear resistance of components operating under
shear conditions. The measured microhardness of the as-cast matrix in samples tested was observed to increase with the increasing content
of titanium and was 380 HV0.02 for the content of 0.4%, 410 HV0.02 for the content of 1.5% and 510 HV0.02 for the content of 2 and
2.5%. After solution heat treatment, the microhardness of the matrix was 460÷480 HV0.02 for melts T2, T3 and T6, and 580 HV0.02 for
melt T4, and was higher than the values obtained in common cast Hadfield steel (370 HV0.02 in as-cast state and 340÷370 HV0.02 after
solution heat treatment). The measured microhardness of alloyed cementite was 1030÷1270 HV0.02; the microhardness of carbides
reached even 2650÷4000 HV0.02.
The article presents the results of the research on thermal actions on the materials occurring in the cross section along the depth of the bridge deck and bituminous pavement during its construction. The impulse to curried out the research was the need to explain the causes of the blistering of bituminous waterproofing membranes and asphalt pavements often observed on the bridge decks. The paper presents the examples of such failures and the analyses of possible mechanisms of the phenomenon. Research indicates a significant influence of all technological processes on the temperature of materials in the cross section as well as daily temperature changes. The probability of initiation of reactions between concrete components with gaseous products has been confirmed in such conditions. The susceptibility of bituminous materials to gas emission and blistering is the subject of a separate study. The research was part of a research project carried out under the contract INNOTECHK3/IN3/50/229332/NCBR /14 [13].
The ecological factor is very important in shaping properties of alloys. It leads to a limitation or elimination, from the surroundings, of harmful elements from the heavy metals group. The so-called eco-brasses group comprises common lead-free brasses containing 10 to 40% of zinc and arsenic brasses of a high dezincification resistance. Among standardized alloys, CW511L alloy ( acc. to EN standard) or MS-60 alloy (acc. to DIN) can be mentioned. Investigations were performed on two different kinds of metal charges: ingots cast by gravity and the ones obtained in the semi-continuous casting technology with using crystallizers. The casting quality was analysed on the basis of the microstructure images and mechanical properties. The investigations also concerned increasing the corrosion resistance of lead-free alloys. This resistance was determined by the dezincification tendency of alloys after the introduction of alloying additions, i.e. aluminium, arsenic and tin. The investigations focused on the fact that not only alloying additions but also the production methods of charge materials are essential for the quality of produced castings. The introduced additions of aluminium and tin in amounts: 0÷1.2 wt% decreased the dezincification tendency, while arsenic, already in the amount of 0.033 wt%, significantly stopped corrosion, limiting the dezincification process of lead-free CuZn37 brass. At higher arsenic contents, corrosion occurs only within the thin surface layer of the casting (20 μ).
The article presents chosen aspects of foundry engineering of the settlement dwellers, including the archaeometric characteristics and
metal science analysis of the artefacts, as well as an attempted reconstruction of the production organization. Discovered in Szczepidło
(Greater Poland), the foundry workshop is unique in Central European Bronze Age.
This workshop foundry operated roughly XIV-XII Century BC. Its production is evidenced by the presence of markers of the whole
production cycle: semi-finished and finished products, production waste, fragments of crucibles and casting ladles with traces of usage,
and tools. On this basis, the alloys and foundry technologies used have been described.
The analysis of foundry technology of copper alloys in the settlement area was carried out by observing the surface and structure of the
products, semi-finished artefacts and fragments of crucibles by applying optical microscopy (OM), confocal microscopy (CLSM) and Xray
radiography (RT). The investigations of compositions were made by means of the energy dispersive X-ray fluorescence spectroscopy
(ED-XRF) and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray analysis system (EDS).
The paper describes the recent developments of Hybrid Fibre-Reinforced Polymer (HFRP) and nano-Hybrid Fibre-Reinforced Polymer (nHFRP) bars. Hybridization of less expensive basalt fibres with carbon fibres leads to more sustainable alternative to Basalt-FRP (BFRP) bars and more economically-efficient alternative to Carbon-FRP (CFRP) bars. The New-Developed HFRP bars were subjected to tensile axial loading to investigate its structural behaviour. The effect of hybridization on tensile properties of HFRP bars was verified experimentally by comparing the results of tensile test of HFRP bars with non-hybrid BFRP bars. It is worth to mention that the difference in obtained strength characteristics between analytical and numerical considerations was very small, however the obtained results were much higher than results obtained experimentally. Authors suggested that lower results obtained experimentally can be explained by imperfect interphase development and therefore attempted to improve the chemical cohesion between constituents by adding nanosilica particles to matrix consistency.
This study characterizes the bronze jewellery recovered from the Lusatian culture urn-field in Mała Kępa (Chełmno land, Poland). Among
many common ornaments (e.g. necklaces, rings, pins) the ones giving evidence of a steppe-styled inspiration (nail earrings) were also
identified. With the dendritic microstructures revealed, the nail earrings prove the implementing of a lost-wax casting method, whereas
some of the castings were further subjected to metalworking. The elemental composition indicates the application of two main types of
bronze alloys: Cu-Sn and Cu-Sn-Pb. It has been established that the Lusatian metalworkers were familiar with re-melting the scrap bronze
and made themselves capable of roasting the sulphide-rich ores.
The collection from Mała Kępa has been described in terms of its structure and composition. The investigations were made by means of
the energy dispersive X-ray fluorescence spectroscopy (ED-XRF), scanning electron microscopy (SEM) coupled with an energy dispersive
X - ray analysis system (EDS) and optical microscopy (OM). In order to fingerprint an alloy profile of the castings with a special emphasis
on the nail earrings, the data-set (ED-XRF, EDS) was statistically evaluated using multidimensional analyses (FA, DA).
The aim of this paper was to attain defect free, pure copper castings with the highest possible electrical conductivity. In this connection, the effect of magnesium additives on the structure, the degree of undercooling (ΔTα = Tα-Tmin, where Tα – the equilibrium solidification temperature, Tmin – the minimum temperature at the beginning of solidification), electrical conductivity, and the oxygen concentration of pure copper castings have been studied. The two magnesium doses have been investigated; namely 0.1 wt.% and 0.2 wt.%. A thermal analysis was performed (using a type-S thermocouple) to determine the cooling curves. The degree of undercooling and recalescence were determined from the cooling and solidification curves, whereas the macrostructure characteristics were conducted based on a metallographic examination. It has been shown that the reaction of Mg causes solidification to transform from exogenous to endogenous. Finally, the results of electrical conductivity have been shown as well as the oxygen concentration for the used Mg additives.
Currently there is a constant development in the field of aluminium alloys engineering. This results from, i.a., better understanding of the
mechanisms that direct strengthening of these alloys and the role of microalloying. Now it is microalloying in aluminum alloys that is
receiving a lot of attention. It affects substantially the macro- and microstructure and kinetics of phase transformation influencing the
properties during production and its exploitation. 7xxx series aluminum alloys, based on the Al-Zn-Mg-Cu system, are high-strength
alloys, moreover, the presence of Zr and Sr further increases their strength and improves resistance to cracking.
This study aims to present the changes of the properties, depending on the alloy chemical composition and the macro- and microstructure.
Therefore, the characteristics in the field of hardness, tensile strength, yield strength and elongation are shown on selected examples.
Observations were made on ingot samples obtained by semi-continuous casting, in the homogenized state.
Samples were prepared from aluminum alloys in accordance with PN-EN 573-3: 2013. The advantage of Al-Zn-Mg-Cu alloys are
undoubtedly good strength, Light-weight and resistance to corrosion. As widening of the already published studies it is sought to
demonstrate the repeatability of the physical parameters in the whole volume of the sample.
Issues connected with high quality casting alloys are important for responsible construction elements working in hard conditions.
Traditionally, the quality of aluminium casting alloy refers to such microstructure properties as the presence of inclusions and intermetallic
phases or porosity. At present, in most cases, Quality index refers to the level of mechanical properties – especially strength parameters,
e.g.: UTS, YS, HB, E (Young’s Modulus), K1c (stress intensity factor). Quality indexes are often presented as a function of density.
However, generally it is known, that operating durability of construction elements depends both on the strength and plastic of the material.
Therefore, for several years now, in specialist literature, the concept of quality index (QI) was present, combines these two important
qualities of construction material. The work presents the results of QI research for casting hypoeutectic silumin type EN AC-42100
(EN AC-AlSi7Mg0.3), depending on different variants of heat treatment, including jet cooling during solution treatment.
Fatigue investigations of two 4XXX0-series aluminum alloys (acc. PN-EN 1706) within a range of fewer than 104 cycles at a coefficient of cycle asymmetry of R = –1 were performed in the current paper. The so-called modified low-cycle test, which provided additional information concerning the fatigue life and strength of the tested alloys, was also performed. The obtained results were presented in the form of diagrams: stress amplitude σa – number of cycles before damage N. On the basis of the microscopic images of sample fractures, the influence of the observed casting defects on the decrease of cycle numbers at a given level of stress amplitude were analyzed. Based on the images and dimensions of the observed defects, stress intensity factor KI was analytically determined for each. Their numerical models were also made, and stress intensity factor KI was calculated by the finite element method (FEM).
The research focuses on assessing the metal content, mainly copper, lead, iron and also silver in metallurgical slag samples from the area
where historical metallurgical industry functioned. In the smelter located in Mogiła, near Krakow (southern Poland), whose operation is
confirmed in sources from 1469, copper was probably refined as well as silver was separated from copper. Based on the change of
chemical and soil phase content and also taking cartographic and historical data into account, considering the restrictions resulting from
the modern land use the area was determined whose geochemical mapping can point to the location of the 15th century Jan Thurzo’s
smelter in Mogiła near Krakow. Moreover, using the same approach with the samples of this kind here as with hazardous waste, an
attempt has been made to assess their impact on the environment. Thereby, taking the geoenvironmental conditions into account, potential
impact of the industrial activity has been assessed, which probably left large scale changes in the substratum, manifested in the structure,
chemical content and soil phase changes. Discovering areas which are contaminated above the standard value can help to identify
historical human activities, and finding the context in artefacts allows to treat geochemical anomalies as a geochronological marker. For
this purpose the best are bed sediments, at present buried in the ground, of historical ditches draining the area of the supposed smelter.
Correlating their qualities with analogical research of archeologically identified slags and other waste material allows for reconstructing
the anthropopressure stages and the evaluation of their effects. The operation of Jan Thurzo’s smelter is significant for the history of
mining and metallurgy of Poland and Central and Eastern Europe.
Cast axes are one of the most numerous categories of bronze products from earlier phases of the Bronze Age found in Poland. They had multiple applications since they were not only used objects such as tools or weapons but also played the prestigious and cult roles.
Investigations of the selected axes from the bronze products treasure of the Bronze Age, found in the territory of Poland, are presented
in the hereby paper. The holder of these findings is the State Archaeological Museum in Warsaw. Metallurgical investigations of axes with bushing were performed in respect of the casting technology and quality of obtained castings. Macroscopic observations allowed to document the remains of the gating system and to assess the range and kind of casting defects. Light microscopy revealed the microstructure character of these relicts. The chemical composition was determined by means of the X-ray fluorescence method with energy dispersion (ED-XRF) and by the scanning electron microscopy with X-ray energy dispersion analysis in micro-areas (SEM-EDS). The shape and dimensions of cores, reproducing inner parts of axes were identified on the basis of the X-ray tomography images. Studies reconstructed production technology of the mould with gating system, determined chemical composition of the applied alloys and casting structures as well as revealed the casting defects being the result of construction and usage of moulds and cores.
The work presents experiment results from the area of copper casting technology and chosen examples of alloyed copper. At present,
copper casting technology is applied in many branches of industrial manufacturing, especially in the sector of construction,
communications, arms and power engineering. Alloyed copper, containing slight additions of different elements and having special
physio-chemical properties, is used in a special range of applications. Copper technology and alloyed copper analyses have been presented,
these materials being used for cast manufacturing for power engineering. The quality of casts has been assessed, based on their
microstructure analysis, chemical content and the cast properties. During the research, special deoxidizing and modifying agents were
applied for copper and chosen examples of alloyed copper; also exemplary samples were tested with the help of metallographic analysis,
electrical conductivity and gaseous impurities research.
High prices of tin and its limited resources, as well as several valuable properties characterising Cu-Sn alloys, cause searching for materials of similar or better properties at lower production costs. The influence of various nickel additions to CuSn10 casting bronze and to CuSn8 bronze of a decreased tin content was tested. Investigations comprised melting processes and casting of tin bronzes containing various nickel additions (up to 5%). The applied variable conditions of solidification and cooling of castings (metal and ceramic moulds) allowed to assess these alloys sensitivity in forming macro and microstructures. In order to determine the direction of changes in the analysed Cu-Sn-Ni alloys, the metallographic and strength tests were performed. In addition, the solidification character was analysed on the basis of the thermal analysis tests. The obtained results indicated the influence of nickel in the solidification and cooling ways of the analysed alloys (significantly increased temperatures of the solidification beginning along with increased nickel fractions in Cu-Sn alloys) as well as in the microstructure pattern (clearly visible grain size changes). The hardness and tensile strength values were also changed. It was found, that decreasing of the tin content in the analysed bronzes to which approximately 3% of nickel was added, was possible, while maintaining the same ultimate tensile strength (UTS) and hardness (HB) and improved plasticity (A5).
This preliminary study characterizes the bronze metalworking on a defensive settlement of the Lusatian culture in former Kamieniec
(Chełmno land, Poland) as it is reflected through casting workshop recovered during recent excavations. Among ready products, the ones
giving evidence of local metallurgy (e.g. casting moulds and main runners) were also identified. With the shrinkage cavities and dendritic
microstructures revealed, the artifacts prove the implementing a casting method by the Lusatian culture metalworkers. The elemental
composition indicates application of two main types of bronzes: Cu-Sn and Cu-Pb. Aside these main alloying additions, some natural
impurities such as silver, arsenic, antimony and nickel were found which may be attributed to the origin of the ore and casting technology.
The collection from Kamieniec was described in terms of its structure and composition. The investigations were made by means of the
energy dispersive X-ray fluorescence spectroscopy (ED-XRF), scanning electron microscopy (SEM) coupled with an energy dispersive Xray
analysis system (EDS) and optical microscopy (OM). In order to fingerprint either local or non-local profile of the alloys, the ED-XRF
data-set was statistically evaluated using a factor analysis (FA).