A review of powder additive manufacturing processes for metallic biomaterials

https://hal.archives-ouvertes.fr/hal-02064113/document

Texture control of 316L parts by modulation of the melt pool morphology in selective laser melting

The effect of laser scanning strategies on texture, mechanical properties, and site-specific grain orientation in selective laser melted 316L SS

In this work, we examined the influence of different types of selective laser melting (SLM) devices on the microstructure and the associated material properties of austenitic 316L stainless steel. Specimens were built using powder from the same powder batch on four different SLM machines. For the specimen build-up, optimized parameter sets were used, as provided by the manufacturers for each individual SLM machine. The resulting microstructure was investigated by means of scanning electron microscopy, which revealed that the different samples possess similar microstructures. Differences between the microstructures were found in terms of porosity, which significantly influences the material properties. Additionally, the build-up direction of the specimens was found to have a strong influence on the mechanical properties. Thus, the defect density defines the material’s properties so that the ascertained characteristic values were used to determine a Weibull modulus for the corresponding values in dependence on the build-up direction. Based on these findings, characteristic averages of the mechanical properties were determined for the SLM-manufactured samples, which can subsequently be used as reference parameters for designing industrially manufactured components.

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Microstructure and mechanical properties of 316L austenitic stainless steel processed by different SLM devices

Five scanning strategies were applied for relating the microstructural and crystallographic morphology to the mechanical properties of 316L stainless steel fabricated by selective laser melting (SLM). The results indicate that scanning strategies have a significant effect on the microstructure, grain growth, grain size and therefore mechanical properties of SLM-built 316L stainless steel. Applying the scanning strategy with the rotation angle between successive layers breaks the columnar growth of grains and fine equiaxial grains are formed, leading to an improvement of tensile strength and good ductility of SLM-built samples. Moreover, the microhardness is improved by applying the scanning strategy with a rectangular pattern. This work demonstrates the scanning strategy during SLM process acts as an essential factor affecting energy input, and therefore tailors the meso-/micro-scale structure and mechanical behavior of metals.

Effect of scanning strategies on the microstructure and mechanical behavior of 316L stainless steel fabricated by selective laser melting

Anisotropy of Mechanical Properties and its Correlation with the Structure of the Stainless Steel 316L Produced by the SLM Method

The properties of dampers manufactured by the selective laser melting are investigated. Microswear with different elastic and plastic properties were found. The texture of dampers samples represents a non-uniform supplement structure of crushed grains, separated by layers with dispersoids of crystallization of varying completion stages.

P.A. Kuznetcov

Papers

Anisotropy of Mechanical Properties and its Correlation with the Structure of the Stainless Steel 316L Produced by the SLM Method

Study of the Structure and the Destruction Surface of the Dampers Manufactured by the Selective Laser Melting