显微组织的影响①
(中南大学粉末冶金国家重点实验室,长沙410083)
摘 要: 用电子探针对Ti-45Al-7Nb-0·15B-0·4W的铸态和经过热处理之后的显微组织进行了观察和分析,并分析了热处理工艺对Ti-45Al-7Nb-0·15B-0·4W显微组织的影响。结果发现: Ti-45Al-7Nb-0·15B-0·4W的铸态组织经过热等静压和均匀化处理后,其晶团尺寸减小,层片组织更为完整; Ti-45Al-7Nb-0·15B-0·4W合金的α相转变温度为(1 290±5)℃; Ti-45Al-7Nb-0·15B-0·4W合金在超过1 295℃的温度进行热处理时,其显微组织由近层片
组织转变为全层片组织。经过热等静压和均匀化处理后Ti-45Al-7Nb-0·15B-0·4W合金的基本形貌为初生γ相+层片状晶团,有β相析出,其形貌为针状、点状、颗粒状。
关键字: 热处理; TiAl;显微组织
Ti-45Al-7Nb-0·15B-0·4W
（ State Key Laboratory of Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract:The microstructures of as-cast and as-heat treated Ti-45Al-7Nb-0·15B-0·4W were observed by electronprobe. The effect of heat treatment process on the microstructure of as-cast and as-heat treated Ti-45Al-7Nb-0·15B-0·4W was discussed. The results show that the microstructure of as-cast Ti-45Al-7Nb-0·15B-0·4W becomes fineafter being HIPped and heat treated, and a more perfect lamellar microstructure is got. The temperature ofαphase
transformation is between 1280℃and 1295℃. The microstructure of Ti-45Al-7Nb-0·15B-0·4W changes fromnear lamella(NL) to full lamella(FL) afterαphase transformation. After the alloy being HIPped and annealed, themicrostructure of Ti-45Al-7Nb-0·15B-0·4W alloy is primaryγphase and lamella, and the needle-like and granularβphase precipitates.
Key words: heat treatment; TiAl; microstructure
