高應(yīng)變速率壓縮變形行為
(北京有色金屬研究總院 復(fù)合材料中心， 北京 100088)
摘 要: 利用Gleeble1500熱模擬機(jī)研究了Zr41.2Ti13.8Cu12.5Ni10Be22.5非晶合金在過冷液相區(qū)內(nèi)633、 653和673 K，應(yīng)變速率分別為2×10-2 s-1和2 ×10-1 s-1條件下的單向壓縮變形行為。結(jié)果表明： 在673 K時兩種應(yīng)變速率下， 該合金都具有很好的塑性， 尤其在2×10-2 s-1時流變應(yīng)力只有74 MPa，非常適于進(jìn)行超塑性加工。 對非晶合金的斷口進(jìn)行了觀察， 得到柱狀非晶合金壓縮變形時外觀和斷口形貌隨著變形條件的變化規(guī)律。 采用自由體積模型對非晶合金的形變和斷裂的微觀機(jī)制進(jìn)行了分析。
關(guān)鍵字: 鋯基塊體非晶合金; 過冷液相區(qū); 變形; 斷裂; 超塑性
（National Engineering Research Center for Nonferrous Metals Composites,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract: The uniaxial compressive deformation behavior of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk amorphous alloy in the supercooled liquid region was studied at 633, 653 and 673 K, and high strain rate of 2×10-2 and 2×10-1 s-1. The result shows that the flow stress and the strain of the alloy strongly depend on the deformation temperature and strain rate. At 673 K, the alloy exhibits good ductility at both strain rates, and particularly at 2×10-2 s-1 its flow stress is only 74 MPa and the alloy is very suitable for superplastic forming. The fracture morphologies of the tested samples were observed by scanning electron microscopy, and the variation of the morphologies of the cylindrical specimens outlines and fracture surfaces with the processing conditions was summarized. The mechanism of the deformation and fracture of the alloy was analyzed by using the free volume model.
Key words: Zr-based bulk amorphous alloy; supercooled liquid region; deformation; fracture; superplasticity
