机械合金化Fe基预合金粉末对金刚石刀头性能的影响

Effects of Fe-based pre-alloy powder by mechanical alloying on properties of diamond tool

探索了Fe-Cu-Ni-X(X=W、Mo、Ti、C、B4C)系粉末的机械合金化工艺,及其对热压烧结金刚石刀头强度和硬度的影响。发现干法球磨20小时可以得到15μm的预合金粉末,除W、B4C之外,其它元素均可固溶入Fe中;经930℃热压烧结后,Cu又从Fe中析出,同时形成WC等硬质相;B4C可能在球磨过程中产生了部分非晶化,经高温烧结后又恢复了结晶态,B4C并未与W、Mo、Ti等合金元素反应形成金属硼化物;将80vol%机械合金化预合金粉末与20vol%的45/50#镀Ti金刚石颗粒均匀混合后,进行930℃热压烧结,随着B4C含量增加,金刚石刀头的硬度逐渐增大,而抗弯强度在1%B4C时达到最高值949MPa,硬度为HRB120.7。

Effects of mechanical alloying processes of Fe-Cu-Ni-X（X=W、Mo、Ti、C、B4C） on bending strength and hardness of the diamond tool samples fabricated by hot press sintering were studied.The testing results show that Fe-based alloying powder with a median particle size of 15μm can be fabricated after 20 hours dry-milling,in which others elements except for W and Cu have reacted with Fe.Cu and WC precipitate from Fe-based matrix after hot press sintering at 930℃.B_4C undergo from non-crystallization in milling to crystallization after sintering,and no metal boride forms after sintering.Diamond tools fabricated by 930℃ hot press sintering of 80vol% Fe-alloying powders and 20%vol Ti coating diamond,has the hardness of HRB120.7 and the maximum bending strength of 949MPa when 1%B_4C is added into Fe-based matrix.