高温TiAl基合金定向凝固的研究现状

摘要

TiAl-based alloy is the potential structural materials for decreasing weight and increasing service temperature. The current status of directional solidification of TiAl-based alloy, a high temperature structural material, is described. The methods to improve the properties of TiAl base alloy are discussed including the high Nb content to improve the resistance and mechanical properties of high temperature, using cold crucible in directional solidification to avoid the contamination from oxide ceramic crucible, the seedon-seed methods t<5 control the lamellar orientation can improve mechanical properties.%高温TiAl基合金在航空航天领域减重和升高使用温度方面是极具发展潜力的高性能结构材料.介绍了高温TiAl基合金定向凝固的研究现状和发展趋势,阐述了提高定向凝固高温TiAl基合金使用性能的几种方法,主要包括:利用高Nb合金化提高合金的使用温度和高温强度,使用冷坩埚定向凝固来避免氧化物陶瓷坩埚带来的合金污染,采用籽晶法/非籽晶法控制定向凝固片层取向以提高力学性能.