自潤滑功能稀土氧硫化物的原位形成
(1. 中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083；
2. 長沙礦冶研究院，長沙 410012)
摘 要: 考察了高活性混合稀土(RE)摻雜的WC-8%Co-0.07%RE(質(zhì)量分?jǐn)?shù))硬質(zhì)合金刀片對鑄鐵的切削試驗。采用掃描電鏡、能譜分析以及X射線衍射等分析方法對硬質(zhì)合金燒結(jié)體表面、切削試驗后刀片的前刀面、后刀面以及切削刃進(jìn)行觀察與分析。結(jié)果表明，在稀土硬質(zhì)合金刀片切削過程中發(fā)生了La、Ce從合金內(nèi)部至刀片工作表面的非同步遷移現(xiàn)象，在刀具工作表面原位形成了具有自潤滑功能的稀土氧硫化物。在實驗觀察與分析基礎(chǔ)上，對La、Ce的定向遷移機(jī)制與稀土氧硫化物的形成機(jī)制進(jìn)行了探討。
關(guān)鍵字: 硬質(zhì)合金；稀土；切削；非同步遷移；自潤滑
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Changsha Mining and Metallurgy Research Institute, Changsha 410012, China）
Abstract: As-sintered high activity mischmetal (RE, with lanthanum and cerium) doped WC-8%Co-0.07%RE (mass fraction) cemented carbide inserts were tested for the turning of cast iron. The sinter skin, flank face, rake face and cutting edge of the inserts after testing were observed and analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry. Asynchronous migration phenomenon of lanthanum and cerium from the inside to the working faces of the as-sintered insert during the turning process was observed. The results show that a rare earth oxysulfide phase with self lubricating function forms in-situ on the working faces of cemented carbide cutting tool. The mechanisms for the directional migration and formation of rare earth oxysulfide were discussed.
Key words: cemented carbide; rare earth; cutting; asynchronous migration; self lubricating
