W,Cr对高铌γ-TiAl基合金高温抗氧化性能的影响  

Influence of W, Cr on the High-temperature Oxidation Resistance of Fourγ -TiAl Based Alloys with High Nb Content

作　　者：丁晓非[1] 沈勇[1] 王秀敏[1] 谭毅[1] 王富岗[1] 

机构地区：[1]大连理工大学,辽宁大连116024

出　　处：《稀有金属材料与工程》2004年第5期543-547,共5页Rare Metal Materials and Engineering

摘　　要：在高铌等原子比的γ-TiAl基金属间化合物的基础上添加W,Cr等元素,熔炼了4种合金,研究了这4种合金在1 000℃静止空气中的断续氧化行为。结果表明:14.3%的高Nb量使合金的抗氧化性显著提高,促进合金形成了以Al2O3为主的连续致密氧化膜;在高铌合金中添加W导致基体中β相的增多,较多的β相削弱了Nb的抗氧化性作用;添加2%的Cr导致氧化膜与基体的粘附性变差,形成的氧化膜在冷却热应力的作用下发生破裂与剥落。合金元素对抗氧化性的影响不是简单的量的叠加。Four alloys were got by adding W, Cr into the equal atom-ratio TiAl-based intermetallic compound with high Nb concent. The interrupted oxidation behavior of the four alloys at 1 000℃ in static air was studied. The results show that addition of 14.3% Nb enhances the oxidation resistance of the alloy greatly and promotes the formation of continuous and compact Al2O3 oxide scale. The addition of W in the high-Nb alloy results more formation of phase in the alloy, which impairs the beneficial effect of Nb. The addition of Cr makes the adhesiveness between oxide and matrix weaked; the formed oxide is liable to break off due to thermal stress during cooling. The influence of alloying elements on the oxidation resistance of the alloy is not simple superposition of the amount.

关 键 词：金属间化合物TiAl 高温氧化 抗氧化性 氧化层 

分 类 号：TG135[一般工业技术—材料科学与工程]