變形行為及結(jié)構(gòu)
(1. 北京有色金屬研究總院 復(fù)合材料中心, 北京100088;
2. 北京有色金屬研究總院 加工工程中心, 北京 100088;
3. 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Zr41.2Ti13.8Cu12.5Ni10Be22.5非晶合金在過(guò)冷液相區(qū)內(nèi)靜液擠壓的變形行為以及結(jié)構(gòu)變化。結(jié)果表明： 非晶合金在高應(yīng)變速率下產(chǎn)生了明顯的塑性變形, 直徑從16 mm變?yōu)?2 mm, 斷裂為4段， 且樣品斷口上隨機(jī)分布著充分發(fā)展與未充分發(fā)展的脈紋式切變帶, 由此可看出非晶合金的變形為非牛頓體變形行為； 擠壓后的樣品約有3％的非晶相發(fā)生晶化, 在非晶基體上析出10～20 nm的納米晶粒, 導(dǎo)致擠壓后非晶合金的熱穩(wěn)定性降低； 靜液擠壓高應(yīng)變速率變形條件使非晶合金產(chǎn)生非均勻流變, 是造成非晶合金斷裂的主要原因。
關(guān)鍵字: ZrTiCuNiBe非晶合金； 塊體非晶合金; 過(guò)冷液相區(qū); 靜液擠壓; 塑性變形
Zr base bulk amorphous alloy in supercooled liquid region by hydrostatic extrusion
XU Jun1, SHI Li-kai1
（ 1. National Engineering Research Center for Nonferrous Metals Composites,
General Research Institute for Non-ferrous Metals, Beijing 100088, China;
2. Nonferrous Metals Processing Engineering Research Center,
General Research Institute for Non-ferrous Metals, Beijing 100088, China;
3. School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China）
Abstract: The deformation behavior and structure of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk amorphous alloy processed at 663 K with strain rate of 0.28 s-1 by hydrostatic extrusion were studied. The results show that the alloy undergoes obvious plastic elongation, the specimen fractures into four sections and the diameter changes from 16 mm to 12 mm. The fracture surfaces distribute randomly well developed and partially developed veinal patterns. The deformation behavior of alloy is non-Newtonian flow behavior. About 3% amorphous matrix of extruded specimen transforms crystal, the crystal particles with size of 10-20 mm are precipitated in the amorphous matrix, the thermostability of the extruded specimen was lowered. The failure of the alloy is mainly attributed to non-uniform viscous flow under high strain rate resulting from the hydrostatic extrusion process.
Key words: ZrTiCuNiBe amorphous alloy; bulk amorphous alloy; supercooled liquid phase region; hydrostatic extrusion; plastic deformation
