Experimental and numerical study on micro-milling of CoCrW alloy produced by selective laser melting and casting

Abstract

CoCrW can be produced using Additive Manufacturing (AM), while casting methods are commonly used for applications such as dental prostheses. However, rapid heating and cooling during AM production can lead to internal defects, micro-cracks, and shrinkage. Micro-milling can help enhance the material’s structure and impart micro-scale properties. This study aimed to investigate the micro-milling properties of CoCrW products manufactured using AM and compare them with materials produced by casting. Numerical models and experimental studies were conducted to examine the differences. Results showed that CoCr alloys produced with AM exhibited 25%–30% lower burr formations, while CoCrW produced by casting had 2%–5% lower surface roughness. Micro-milling experiments demonstrated that a feed rate of 2.5 μm/tooth resulted in 35%–40% more burr formation and surface roughness compared to a feed rate of 5 µm/tooth in both SLM and casting methods, attributed to the cutting edge radius. The cutting temperature and top burr height were analyzed using finite element simulations and experimental methods. It was observed that the maximum temperature in CoCrW produced by casting was 6%–15% higher than that in the SLM method. The finite element analyses and experiments revealed a difference of 4%–7% in maximum temperatures and top burr height.