( 北京科技大學(xué) 材料科學(xué)與工程學(xué)院， 北京 100083)
摘 要: 研究了Zr41.25Ti13.75Ni10Cu12.5Be22.5大塊非晶合金的過冷溫度區(qū)域范圍、 時(shí)間—溫度—轉(zhuǎn)變曲線及其在過冷溫度區(qū)域的力學(xué)行為， 并在此基礎(chǔ)上， 對(duì)精密凸輪零件進(jìn)行了模鍛成形實(shí)驗(yàn)， 分析了不同溫度和應(yīng)變速率對(duì)成形結(jié)果的影響。 結(jié)果表明： Zr41.25Ti13.75Ni10Cu12.5Be22.5大塊非晶合金在635.6~710.4K的過冷區(qū)域范圍內(nèi)， 其應(yīng)變速率敏感系數(shù)接近1， 具有良好的超塑性性能； 較理想的超塑性成形溫度為653~668K， 應(yīng)變速率為5.0×10-4 ~5.0×10-3 s-1。 在溫度為668K、 應(yīng)變速率為5.0×10-4 s-1的工藝條件下， 非晶合金的可成形時(shí)間大于1000s， 最大流動(dòng)應(yīng)力小于70MPa。
關(guān)鍵字: 大塊非晶合金； 過冷區(qū)域； 超塑性； 成形
ZHOU Cheng, XIE Jian-xin
（ School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China）
Abstract: Super-cooled liquid region, time-temperature-transformation diagram, and mechanical behavior of Zr41.25Ti13.75Ni10Cu12.5Be22.5 in the super-cooled liquid region were investigated , and based on which , precision cams are fabricated by using die forging method. The effects of different temperatures and different strain rates on the formability were analyzed. The results show that Zr41.25Ti13.75Ni10Cu12.5Be22.5 bulk amorphous alloy exhibits a good superplasticity formability in the super-cooled liquid region of 635.6-710.4K with the strain rate sensitivity exponent m-value being approximately 1.0. The acceptable temperature and strain rate range for superplastic forming of this material are 653 -668K and 5.0×10-4 -5.0×10-3 s-1 respectively. Under the processing conditions of 668K and 5.0×10-4s-1, the incubation time for retaining the glassy phase without decomposition reaches 1000s and the largest flow stress is less than 70 MPa.
Key words: bulk amorphous glass; super-cooled liquid state; superplasticity; forming
