掺杂EBS润滑剂的粉末冶金铝合金脱脂工艺研究

文章通过冷压-烧结制备了掺杂EBS润滑剂的粉末冶金铝合金,比较了单/多温段脱脂工艺优劣,发现多温段脱脂优于单温段脱脂,脱脂更彻底,但由于气体流量不能无限大,导致气氛脱脂得到的样品碳含量无法达到碳剩余理论值0.02%。研究了真空脱脂和空气负压脱脂机制,真空脱脂可使得EBS热分解的气态有机物和灰分从压坯表面逸出,并被及时带出炉外,最终合金碳含量接近碳剩余理论值0.02%；空气负压脱脂可使得残余碳被氧化逸出,脱碳更彻底,使样品碳含量低于碳剩余理论值。研究了脱脂工艺对合金力学性能的影响,真空脱脂合金力学性能优于气氛脱脂,相对密度最大为97.86%,拉伸强度最大为218.06MPa,接近未添加润滑剂合金的力学性能；空气负压脱脂虽然可使碳含量更低,但因脱脂过程中样品暴露在空气中,使得原料粉末也被氧化,导致最终的合金力学性能严重下降。

Study on the debinding process of powder metallurgy aluminum alloy prepared by doping EBS lubricants

Powder metallurgy aluminum alloy was prepared by cold press-sintering, and the advantages and disadvantages of single/multi-temperature degreasing process were compared. It was found that multi-temperature debinding is better than single-temperature debinding, and the debinding is more thorough. Vacuum debinding and air negative pressure debinding mechanism were studied. Vacuum debinding allows gaseous organic matter and ash that are thermally decomposed by EBS to escape from the surface of the pressed billet and be taken out of the furnace in time. The final carbon content of the alloy is close to the theoretical value of 0.02%. Air negative pressure debinding can make the residual carbon be oxidized and escaped, and the carbon content of the sample is lower than the theoretical value of carbon residue. The effect of debinding process on the mechanical properties of the alloy was studied. The mechanical properties of vacuum debinding alloy were better than that of atmosphere debinding, with the maximum relative density of 97.86% and the maximum tensile strength of 218.06MPa, which were close to the mechanical properties of the alloy without lubricant. Although air negative pressure debinding can lower the carbon content, the raw material powder is oxidized due to the exposure of samples to air during the debinding process, resulting in a serious decline in the mechanical properties of the final alloy.