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In this paper, the mechanical properties and corrosion resistance of CoCr alloy fabricated by selective laser melting (SLM) were studied, and the changes of performance after porcelain sintering process were also analysed. This study is to point out the relationship between the microstructure, mechanical properties and corrosion resistance of CoCr alloys prepared by SLM after porcelain sintering process. In addition, the biosafety of the sintered CoCr alloy was evaluated.

The microscopic feature changes of CoCr alloy samples after porcelain sintering process were observed by DMI 5000 M inverted metallographic microscope and Nova Nano430 FE-SEM. Moreover, phase identification and determination were conducted by X-ray diffraction (XRD) using Smartlab X-ray diffractometer. The Vickers microhardness was measured on the HVS-30 microhardness tester, and tensile tests were carried out on a CM3505 electronic universal testing machine. The corrosion resistance was tested by a classical three-point electrode system electrochemical method, then the ion precipitation was measured by using an atomic absorption spectrometer of Z2000 7JQ8024.

The XRD results indicate that the transition of γ phase (FCC) to e phase (HCP) occurs during the porcelain sintering processing of CoCr alloy. Moreover, the Vickers microhardness of the upper surface and the side surface of the CoCr alloy sample was improved by more than 36%. In addition, the ultimate strength of CoCr alloy via porcelain sintering treatment was increase to 1,395.3 ± 53.0 MPa compared to 1,282.7 ± 10.1 MPa of unprocessed CoCr alloy. However, the corrosion resistance of CoCr alloy samples decreases after porcelain sintering process.

There are few studies on the relationship of microstructure, mechanical properties and corrosion resistance of CoCr alloys prepared by SLM after porcelain sintering process. In this study, the microstructure, mechanical properties and corrosion resistance of CoCr alloy after porcelain sintering process were studied, and the biosafety of the alloy was evaluated. The research found that it is feasible to apply CoCr alloy fabricated by SLM to dental medicine after porcelain sintering process.

This study aims to focus on the optimized design and mechanical properties of gradient triply periodic minimal surface cellular structures manufactured by selective laser melting.

Uniform and gradient IWP and primitive cellular structures have been designed by the optimized function in MATLAB, and selective laser melting technology was applied to manufacture these cellular structures. Finite element analysis was applied to optimize the pinch-off problem, and compressive tests were carried out for the evaluation of mechanical properties of gradient cellular structures.

Finite element analysis shows that the elastic modulus of IWP increased as design parameter b increased, and then decreased when parameter b is higher than 5.5. The highest elastic modulus of primitive increased by 89.2% when parameter b is 6. The compressive behavior of gradient IWP and primitive shows a layer-by-layer way, and elastic modulus and first maximum compressive strength of gradient primitive are higher than that of gradient IWP. The effective energy absorption of gradient cellular structures increased as the average porosity decreased, and the effective energy absorption of gradient primitive is about twice than that of gradient IWP.

This paper presents an optimized design method for the pinch-off problem of gradient triply periodic minimal surface cellular structures.

This study aims to achieve customized prosthesis for total joint arthroplasty and total hip arthroplasty. Selective laser sintering (SLS) as additive manufacturing could enable small-scale fabrication of customized Ultra High Molecular Weight Polyethylene (UHMWPE) components; however, the processes for SLS of UHMWPE need to be improved.

This paper begins by improving the preheating system of the SLS fabricating equipment and then fabricating cuboids with the same size and cuboids with same volume and different size to study the warpage, demonstrating the effect of the value and uniformity of the preheating temperature on component fabrication. Warpage, density and tensile properties are investigated from the perspective of energy input density. Finally, complicated industrial parts are produced effectively by using optimized technological parameters.

The results show that components can be fabricated effectively after the optimization of the SLS technological parameters i.e. the preheating temperature the laser power the scanning interval and the scanning speed. The resulting warpage was found to be less than 0.1 mm along with the density as 83.25 and the tensile strength up to 14.1 Mpa. UHMWPE sample parts with good appearance and strength are obtained after ascertaining the effect of each factor on the fabrication of the sample parts.

It is very challenging to fabricate UHMWPE sample parts by SLS. This is a new step in the fabrication of customized UHMWPE sample parts.

This paper aims to achieve rapid design and manufacturing of personalized total knee femoral component.

On the basis of a patient’s bone model, a matching personalized knee femoral component was rapidly designed with the help of computer-aided design method, then manufactured directly and rapidly by selective laser melting (SLM). Considered SLM as manufacturing technology, CoCrMo-alloyed powder that meets ASTM F75 standard is made of femoral component under optimal processing parameters. The feasibility of SLM forming through conducting experimental test of mechanical properties, surface roughness, biological corrosion resistance was analyzed.

The result showed that the tensile strength, yield strength, hardness and biological corrosion resistance of CoCrMo-alloyed personalized femoral component fulfill knee joint prosthesis standard through post-processing.

Traditional standardized prosthesis implantation manufacturing approach was changed by computer-aided design and personalized SLM direct manufacturing, and provided a new way for personalized implanted prosthesis to response manufacturing rapidly.

This study aims to focus on the heat treatment influence on the corrosion resistance, adhesion of Streptococcus mutans and mechanical properties of CoCrMo alloys manufactured by the selective laser melting (SLM).

CoCrMo alloys were manufactured using the Dimetal-100 machine. X-ray diffraction (XRD), metallographic analysis, scanning electron microscopy (SEM), electrochemical corrosion, Vickers microhardness and tensile tests were used to characterize SLM-produced CoCrMo alloys and compare them with the ones manufactured by casting and with the ASTM F75 standard.

The electrochemical results showed that SLM900 samples had the best corrosion resistance in artificial saliva. The adhesion results showed least propagation and overall quantity of Streptococcus mutans on the SLM900 sample. The microhardness, tensile and yield strength of As-SLM, SLM900 and SLM1200D samples were measured according to the ASTM F75 standard. The elongation of SLM900 was less than 8 per cent, which does not meet the standard specifications. Analysis of the fracture morphology showed that the fracture mechanisms of As-SLM and SLM1200D belong to the quasi-cleavage fracture type, and the mechanical fracture mechanism of SLM900 can be characterized as brittle fracture.

This paper presents the adhesion properties of Streptococcus mutans on the surface of CoCrMo alloys manufactured by SLM and proposes how to regulate the effect of the heat treatment on the corrosion resistance and mechanical properties of CoCrMo alloys manufactured by SLM.

This paper aims to better control the mechanical properties and functional properties of NiTi alloy.

NiTi alloy samples with equal atomic ratio were formed by selective laser melting (SLM). X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy and tensile testing methods were used to study the effects of different laser power and scanning speed on the densification behavior, phase transformation characteristics and mechanical properties of NiTi alloy.

Compared with the laser power, the variation of the keyhole effect caused by the change of scanning speed is more intense, which has a greater effect on the densification behavior of SLM NiTi alloy. The effect of the laser power on the phase transition temperature is small. The increase of scanning speed weakens the burning degree of Ni element, so phase transition temperature decreases. The results of DSC test and tensile test show that the scanning velocity can significantly change the phase transition temperature, martensite twins reorientation and stress–strain behavior of SLM NiTi alloy.

This study provides a potential method to regulate the mechanical properties and functional properties of NiTi shape memory alloy in the future and NiTi alloys formed by SLM with good elongation were obtained because the Supercellular crystal structure formed during the nonequilibrium solidification of SLM and the superfine precipitates dispersed in the alloy prevented the dislocation formation.

The purpose of this paper is to provide a theoretical foundation for improving the selective laser melting (SLM) surface roughness. To improve the part’s surface quality during SLM process, the upper surface roughness of SLM parts was theoretically studied and the influencing factors were analyzed through experiments.

The characteristics of single track were first investigated, and based on the analysis of single track, theoretical value of the upper surface roughness would be calculated. Two groups of cubic sample were fabricated to validate SLM parts’ surface roughness, the Ra and relative density of all the cubic parts was measured, and the difference between theoretical calculation and experiment results was studied. Then, the effect of laser energy density on surface roughness was studied. At last, the SLM part’s surface was improved by laser re-melting method. At the end of this paper, the curved surface roughness was discussed briefly.

The SLM upper surface roughness is affected by the width of track, scan space and the thickness of powder layer. Measured surface roughness Ra value was about 50 per cent greater than the theoretical value. The laser energy density has a great influence on the SLM fabrication quality. Different laser energy density corresponds to different fabricating characteristics. This study divided the SLM fabrication into not completely melting zone, balling zone in low energy density, successfully fabricating zone and excessive melting zone. The laser surface re-melting (LSR) process can improve the surface roughness of SLM parts greatly without considering the fabricating time and stress accumulation.

The upper surface roughness of SLM parts was theoretically studied, and the influencing factors were analyzed together; also, the LSR process was proven to be effective to improve the surface quality. This study provides a theoretical foundation to improve the surface quality of SLM parts to promote the popularization and application of metal additive manufacturing technology.

This paper aims to explore a structural optimization method to achieve the lightweight design of an aviation control stick part manufactured by laser powder bed fusion (LPBF) additive manufacturing (AM). The utilization of LPBF for the fabrication of the part provides great freedom to its structure optimization, further reduces its weight and improves its portability.

The stress distribution of the model was analyzed by finite element analysis. The material distribution path of the model was optimized through topology optimization. The structure and size of the parts were designed by applying honeycomb structures for weight reduction. The lightweight designed control stick part model was printed by LPBF using AlSi10Mg.

The weight of the control stick model was reduced by 32.64% through the optimization method using honeycomb structures with various geometries. The similar stress concentrations of the control stick model indicate that weight reduction has negligible effect on its mechanical strength. The maximum stress of the lightweight designed model under loading is 230.85 MPa, which is 61.81% larger than that of the original model. The lightweight control stick part manufactured by LPBF has good printability and service performance.

A structural optimization method integrating topology, shape and size optimization was proposed for a lightweight AlSi10Mg control stick printed by LPBF. The effectiveness of the optimization method, the printability of the lightweight model and the service performance of LPBF-printed AlSi10Mg control stick was verified, which provided practical references for the lightweight design of AM.

This paper aims to analyze the different between matrix and overhanging structure and indicate the laws and mechanism of overhanging structure formed by selective laser melting (SLM).

This paper includes processing the matrix and overhanging structure with optimized parameters and analyzing the microstructure and properties of matrix and overhanging with OM, SEM, XRD etc. so as to analyze and reveal the laws and mechanism of overhanging structure formed by SLM.

The solidification of overhanging structure begins from the structure’s edge and extends to its center; the distribution of the Cr with a diameter of 250 nm in the Fe matrix is uniform; the grain in the overhanging structure is growing faster than the grain in the matrix. The overhanging structure mainly composed by austenite has no apparent layer. Moreover, the microhardness of the overhanging structure is 258.6-294.0 Hv0.3, smaller than the microhardness of the matrix which is 236.4-300.9 Hv0.3.

This paper clarifies how to manufacture overhanging structure and non-overhanging structure matrix with optimized parameters, analyzes the microstructures and compares the properties of both overhanging structure and non-overhanging structure “matrix”, so as to analyze the reasons for the forming of the overhanging structure, which in turn lauds basic data foundation for the theoretical studies in the future.

The purpose of this study is focused on the mechanical properties of multi-materials porous structures manufactured by selective laser melting (SLM).

The Diamond structure was designed by the triply periodic minimal surface function in MATLAB, and multi-materials porous structures were manufactured by SLM. Compression tests were applied to analyze the anisotropy of mechanical properties of multi-materials porous structures.

Compression results show that the multi-materials porous structure has a strong anisotropy behavior. When the compression force direction is parallel to the material arrangement, multi-materials porous structure was compressed in a layer-by-layer way, which is the traditional deformation of the gradient structure. However, when the compression force direction is perpendicular to the material arrangement, the compression curves show a near-periodic saw-tooth waveform characteristic, and this kind of structure was compressed consistently. It is demonstrated that the combination with high strength brittle material and low strength plastic material improves compression mode, and plastic material plays a role in buffering fracture.

This research provides a new method for the design and manufacturing of multi-materials porous structures and an approach to change the compression behavior of the porous structure.