摘要
烧结硬化使粉末冶金零件可在一般烧结炉的冷却带进行硬化 ,而不需要在烧结后进行热处理。为开发用于可再充电的电动工具用的高速、高扭矩齿输 ,试验了掺加有 2 0 %Cu与 0 90 %石墨的预合金化粉末ATOMET 4 70 1 (0 4 5Mn - 0 4 5Cr - 0 9Ni- 1 0Mo)。将零件生坯压制到密度 6 85 g/cm3 ,在 1 1 2 0℃下于吸热性煤气气氛中烧结 30min。烧结态零件 (密度 6 80g/cm3 )的表观硬度为 37HRC。显微组织分析表明 ,在烧结炉冷却带充分产生了马氏体相变。随后 ,零件在 1 80～ 2 1 0℃下回火 0 5～ 4h。在 1 80℃回火 2h后 ,烧结硬化材料的力学性能与齿输齿的精度处于最佳结合状态 。
Sinter hardening enables P/M parts to be hardened in conventional sintering furnaces,eliminating the need for post sintering heat treatments A pre alloy powder(0 45Mn 0 45Cr 0 90Ni 1 0Mo),ATOMET 4701,admixed with 2 0% copper and 0 9% graphite was tested to develop high speed and high torque gears used for rechargeable power hand tools The parts were pressed to a green density of 6 85g/cm 3 and sintered in an endothermic atmosphere at 1120℃ for 30 minutes The apparent hardness of as sintered parts reached 37 HRC at 6 8g/cm 3 The microstructure analysis revealed a full martensite transformation occurred in the cooling zone of the sinter furnace The parts were subsequently tempered at 180～210℃ for 0 5 to 4 hours The sinter hardening material yielded the optimal combination of mechanical properties and gear tooth accuracy after tempering at 180℃ for 2 hours,which were superior to the heat treated low alloyed material
出处
《粉末冶金技术》
CAS
CSCD
北大核心
2003年第6期334-337,共4页
Powder Metallurgy Technology
