Effects of Gas Pressure during Electron Beam Energy Deposition in the EBM Additive Manufacturing Process

Metals

Dor Braun¹  Michael Chonin¹  Itzhak Orion²  YaronItay Ganor³  Elroei Damri³  Eitan Tiferet³ 

[1] AM R&D Center, AM Center, Rotem Industries, Mishor Yamin 86800, Israel;Department of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel;Nuclear Research Center (NRCN), P.O. Box 9001, Beer-Sheva 84190, Israel;

关键词: additive manufacturing;    electron beam melting;    Monte Carlo simulations;    experimental validation;    helium;   

DOI  :  10.3390/met11040601

来源: DOAJ

【 摘 要 】

Electron beam melting (EBM) is a metal powder bed fusion additive manufacturing (AM) technology that facilitates the production of metal parts by selectively melting areas in layers of metal powder. The electron beam melting process is conducted in a vacuum chamber environment regulated with helium (He) at a pressure on the scale of 10⁻³ mbar. One of the disadvantages of vacuum environments is the effect of vapor pressure on volatile materials: indeed, elements in the pre-alloyed powder with high vapor pressure are at risk of evaporation. Increasing the He pressure in the process can improve the thermodynamic stability of the pre-alloyed components and decrease the composition volatility of the solid. However, increasing the pressure can also attenuate the electrons and consequently reduce the energy deposition efficiency. While it is generally assumed that the efficiency of the process is 90%, to date no studies have verified this. In this study, Monte Carlo simulations and detailed thermal experiments were conducted utilizing EGS5 and an Arcam Q20+ machine. The results reveal that increasing the gas pressure in the vacuum chamber by one order of magnitude (from 10⁻³ mbar to 10⁻² mbar) did not significantly reduce the energy deposition efficiency (less than 1.5%). The increase in gas pressure will enable the melting of alloys with high vapor pressure elements in the future.

【 授权许可】

Unknown