Effect of Subsequent Hot Isostatic Pressing on Mechanical Properties of ASTM F75 Alloy Produced by Selective Laser Melting

摘要

The Co-based alloy ASTM (Co – 28.5 wt.-% Cr – 6.3 wt.-% Mo) is widely used for medical implants,e.g. knee prostheses, and is commonly processed by investment casting. Selective laser (SLM)melting is supposed to be an efficient alternative for the production of individually designed kneeimplants regarding production time and production costs. The mechanical properties, in particular thefatigue strength, of the material have been studied in different states of the material. The mechanicalproperties of investment casted ASTM F75 and PM-SLM produced ASTM F75 were investigated. Thefocus in this study was on the PM-SLM material, the specimens were initially produced by selectivelaser melting and a part of the specimens were further processed by hot isostatic pressing (HIP). ThePM-SLM material was mechanically tested in the as-SLM state as well as in the SLM+HIP state. It wasfound that the mechanical properties of the as-SLM material did not reach the level of the fatiguestrength of as cast material. The post-densification treatment by HIP offers distinct improvementsregarding the fatigue strength compared to the as-SLM material.