Investigation into Effects of Scanning Speed on in Vitro Biocompatibility of Selective Laser Melted 316L Stainless Steel Parts

Yitong Shang,Dongfang Li,Yongzhi Zhang,Yanping Yuan,Yansheng Li,H.L Yuan,R.K Agarwal,E.X Wang,P Tandon

doi:10.1051/matecconf/20179501009

Abstract

In recent years, selective laser melting (SLM) has gained an important place in fabrication due to their strong individualization which cannot be manufactured using conventional processes such as casting or forging. By proper control of the SLM processing parameters, characteristics of the alloy can be optimized. In the present work, 316L stainless steel (SS), as a widely used biomedical material, is investigated in terms of the effects of scanning speed on in vitro biocompatibility during SLM process. Cytotoxicity assay is adopted to assess the in vitro biocompatibility. The results show the scanning speed strongly affects the in vitro biocompatibility of 316L SS parts and with prolongs of incubation time, the cytotoxicity increase and the in vitro biocompatibility gets worse. The optimal parameters are determined as follows: scanning speed of 900 mm/s, laser power of 195 W, hatch spacing of 0.09 mm and layer thickness of 0.02 mm. The processing parameters lead to the change of surface morphology and microstructures of samples, which can affect the amount of toxic ions release, such as Cr, Mo and Co, that can increase risks to patient health and reduce the biocompatibility.

Highlights

With an increased demand for fast and less expensive product development, rapidly manufacturing parts from metal powders without moulds becomes more and more desirable [1,2]
Laser melting and numerical simulation of 316L powder have been used to evaluate the influence of laser power, scanning speed and beam size on the melting zone and the phenomenon of the ball performed by Antony etal
The material used in our experiments is 316L stainless steel powder, manufactured via gas atomization, as shown in Fig. 2 and Fig. 3

Summary

Introduction

With an increased demand for fast and less expensive product development, rapidly manufacturing parts from metal powders without moulds becomes more and more desirable [1,2]. The release of potential toxic ions such as Cr, Ni and Mo, in 316L parts manufactured via the SLM route, prevents its use for applications in dental prostheses, which increases risks to patient health. The properties of SLM shaped parts are influenced by the process parameters, such as the scanning speed, the laser power and the scanning distance [12, 13].

Results

Conclusion