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This paper aims to discuss the results of material tests conducted on specimens manufactured from AZ31 alloy powder by selective laser melting (SLM) technology. The manufactured specimens were then subjected to porosity assessment, microstructure analysis as well as to mechanical and corrosion tests.

SLM process was optimized using the design of experiments tools. Experiments aimed at selecting optimum process parameters were carried out in accordance with a five-level rotatable central composite design.

The porosity results showed very low values of <1 per cent, whereas mechanical properties were close to the values reported for the reference wrought AZ31 alloy in hot-rolled state. A fine-grained microstructure was observed with a large range of grain size, which enhanced the material’s mechanical properties. Corrosion characteristics of the SLM-manufactured material exceed those determined for the wrought material.

The results presented in this paper drive interest in magnesium alloys used in additive manufacturing processes. Low porosity, good mechanical properties, form of the microstructure and, most importantly, improved corrosion characteristics suggest that SLM provides great potential for the manufacture of ultralight structures, including resorbable metallic implants.

This paper aims to present the way of modifying surfaces of 316L stainless steel elements that were manufactured in the selected laser melting (SLM) technology and then subjected to mechanical and electrolytic processing (electropolishing [EP]). The surface of the as-generated and commercial produced parts was modified by grinding and EP, and the results were compared. The authors also present an example of the application of EP for the final processing of a sample technological model – an initial prototype of a 316L steel implant manufactured in the SLM technology.

The analyzed properties included surface topography, roughness, resistance to corrosion, microhardness and the chemical composition of the surface before and after EP. The roughness described with the Ra, Rt and Rz was determined before and after EP of samples manufactured from 316L steel with use of traditional methods and additive technologies.

EP provides us with the opportunity to process elements with a complex structure, which would not be possible with use of other methods (such as milling or grinding). Depending on the expected final surface of elements after the SLM process, it is possible to reduce the surface roughness with the use of EP (for t = 20 min, Ra = 3.53 ± 0.37 µm and for t = 40 min, Ra = 3.23 ± 0.22 µm) or mechanical processing and EP (for t = 4 min, Ra = 0.13 ± 0.02 µm). The application of the EP method to elements made from 316L steel, in a bath consisting of sulfuric acid (VI), H2SO4 (35 Vol.%), phosphoric acid (V), H3PO4 (60.5 Vol.%) and triethanolamine 99 per cent (4.5 Vol.%), allows us to improve the surface smoothness and to obtain a value of the Ra parameter ranging from 0.11 to 0.15 µm. The application of a current density of 20 A/dm2 and a bath temperature of 55ºC results in an adequate smoothing of the surface (Ra < 0.16 µm) for both cold rolled and SLM elements after grinding. The application of EP, to both cold rolled elements and those after SLM, considerably improves the resistance to corrosion. The results of potentiodynamic corrosion resistance tests (jkor, EKA and Vp) of the 316L stainless steel samples demonstrate that the values of Vp for elements subjected to EP (commercial material: 1.3·10-4 mm/year, SLM material: 3.5·10-4 mm/year) are lower than for samples that were only ground (commercial material: 4.0·10-4 mm/year, SLM material: 9.6·10-4 mm/year). The microhardness was found to be significantly higher in elements manufactured using SLM technology than in those cold rolled and ground. The ground 316L steel samples were characterized by a microhardness of 318 HV (cold rolled) and 411 HV (SLM material), whereas the microhardness of samples subjected to EP was 230 HV (commercial material) and 375 HV (SLM material).

The 316L samples were built by SLM method. The surface of the SLM samples was modified by EP. Surface morphological changes after EP were studied using optical methods. Potentiodynamic tests enabled to notice changes in the corrosion resistance of 316L. Microhardness results after electropolished 316L stainless steel were shown. The chemical composition of 316L surface samples was presented. The smoothening of the surface amounted to Ra = 0.16 µm.

To show necessity of risk evaluation during modelling and simulation of production systems. To show an approach to risk evaluation of manufacturing system which has serial reliability structure.

Modelling and simulation of a manufacturing system allows one to conduct verification of different solutions in the area of production planning, before they are started. This is impossible with traditional methods.

Reliable results of simulation research can be obtained only if they are based on an integrated model of the company, that covers all components of the manufacturing process including also its organization and risk in production processes.

The paper describes the stages and results of a project carried out in 2002 in an international company. The proposed method of risk evaluation may be helpful to determine the risk level in the chosen production line and eventually for the whole enterprise manufacturing systems.

The risk concept was treated as a synonym of unreliability. This kind of approach enabled decomposition of the production system into several areas and determination of the reliability structure.

The purpose of this paper is to present the results of theoretical considerations and experimental tests concerning microscaffold fabrication by selective laser melting (SLM). Also described are manufacturing technologies for regular lattice microstructure with the smallest possible pore sizes and fullest possible order of geometric accuracy retained. Process parameters of SLM greatly affect the properties of the fabricated structures not only in regards to their material characteristics but also in their geometric representation accuracy.

The paper discusses technological relationships between different laser micrometallurgy strategies and the accuracy of the manufactured microstructures.

With technological possibilities evaluated, regular porous structure was created composed of cubic pores with cylindrical struts as their boundaries. Strut diameters are up to 180 μm, and the distance between neighboring strut axes was reduced to 600 μm, which gives a hollow channels clearance of approximately 420 μm.

Presented results show possibilities of manufacturing small high-strength lattice microstructures by SLM using Ti-6Al-7Nb titanium alloy powders for tissue engineering.