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.
The article presents the technology of layered casting with the use of 3D printing to make a frame insert. The insert was made of powdered titanium and then filled with liquid cast iron. The paper presents the results of research, including structure observation and hardness measurements, as well as abrasion resistance tests. The results indicate the possibility of creating a local reinforcement using a frame insert. The resulting casting is characterized by a local increase in hardness and, in addition, an increase in abrasion resistance of the entire surface layer. The quality of the obtained connection depends strongly on the casting parameters.
The article presents the results of a comparative analysis of the metal substructure for dental prosthesis made from a Co-Cr-Mo-W alloy by
two techniques, i.e. precision investment casting and selective laser melting (SLM). It was found that the roughness of the raw surface of
the SLM sinter is higher than the roughness of the cast surface, which is compensated by the process of blast cleaning during metal
preparation for the application of a layer of porcelain. Castings have a dendritic structure, while SLM sinters are characterized by a
compact, fine-grain microstructure of the hardness higher by about 100 HV units. High performance and high costs of implementation the
SLM technology are the cause to use it for the purpose of many dental manufacturers under outsourcing rules. The result is a reduction in
manufacturing costs of the product associated with dental work time necessary to scan, designing and treatment of sinter compared with
the time needed to develop a substructure in wax, absorption in the refractory mass, casting, sand blasting and finishing. As a result of
market competition and low cost of materials, sinter costs decrease which brings the total costs related to the construction unit making
using the traditional method of casting, at far less commitment of time and greater predictability and consistent sinter quality.
Selective Laser Melting (SLM) is a modern manufacturing method with many applications in medicine, aerospace and automotive industries. SLM processed materials are characterized by good dimensional accuracy and properties comparable or superior to materials obtained by traditional processing methods. In this paper an SLM process was used to obtain 316L stainless steel parts. This paper presents the microstructure, chemical and phase composition, physicochemical and electrochemical properties of 12 groups of tested samples, differentiated by the SLM processing parameters. Based on the investigation, it can be inferred that the selection of the appropriate SLM parameters is very important to determined final material properties. The samples produced with the energy density E = 600 J/mm3 were observed to possess optimum properties – a homogeneous structure, density closest to the desired one, good wettability and pitting corrosion resistance.
The aim of the paper is the residual stress analysis of AlSi10Mg material fabricated by selective laser melting (SLM). The SLM technique allows to product of complex geometries based on three-dimensional model, in which stiffness and porosity can be precisely designed for specific uses. As the studied material, there were chosen solid samples built in two different directions: parallel (P-L) and perpendicular (P-R) to the tested surface and cellular lattice built in perpendicular direction, as well. In the paper, for the complex characterization of obtained materials, the phase analysis, residual stress and texture studies were performed. The classical non-destructive sin2ψ method was used to measure the residual stress measurements.
The final products, both solid sample and cellular lattice, have a homogeneous phase composition and consist of solid solution Al(Si) (Fm-3m) type, Si (Fd-3m) and Mg2Si (Pnma). The obtained values of the crystallite size are in a range of 1000 Å for Al(Si), 130-180 Å for Si phase. For Mg2Si phase, the crystallite sizes depend on sintering process, they are 800 Å for solid samples and 107 Å for cellular lattice. The residual stress results have the compressive character and they are in a range from –5 to –15 MPa.
Industries that rely on additive manufacturing of metallic parts, especially biomedical companies, require material science-based knowledge of how process parameters and methods affect the properties of manufactured elements, but such phenomena are incompletely understood. In this study, we investigated the influence of selective laser melting (SLM) process parameters and additional heat treatment on mechanical properties. The research included structural analysis of residual stress, microstructure, and scleronomic hardness in low-depth measurements. Tensile tests with specimen deformation analysis using digital image correlation (DIC) were performed as well. Experiment results showed it was possible to observe the porosity growth mechanism and its influence on the material strength. Specimens manufactured with 20% lower energy density had almost half the elongation, which was directly connected with the porosity growth during energy density reduction. Hot isostatic pressing (HIP) treatment allowed for a significant reduction of porosity and helped achieve properties similar to specimens manufactured using different levels of energy density.
Microstructure and wear property of AlSi10Mg alloy manufactured by selective laser melting (SLM) were investigated. Also, the effect of post heat treatment on the mechanical and wear properties was examined. Two kinds of heat treatments (direct aging (DA) and T6) were separately conducted to SLM AlSi10Mg alloy. As-built alloy had a cellular structure formed inside the molten pool. Eutectic Si was also observed at the cellular boundary in as-built alloy. After DA heat treatment, the cellular structure still remained, and a large amount of nano-size Si particles were newly formed inside the cell structure. Both molten pool and cellular structure disappeared, and the size of Si increased in T6 alloy. The values of Vickers hardness measured as 139.4 HV (DA alloy), 128.0 HV (As-built alloy) and 85.1 HV (T6 alloy), respectively. However, concerning to wear property, T6 alloy showed better wear resistance than other alloys. The correlation between microstructure and wear mechanism of SLM AlSi10Mg alloy was also discussed.
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