材料工程Issue(6)：5-11,7.DOI:10.3969/j.issn.1001-4381.2013.06.002
热处理对定向凝固Nb-Ti-Si基超高温合金组织及显微硬度的影响
Effects of Heat Treatments on the Microstructure and Microhardness of Directionally Solidified Nb-Ti-Si Based Ultrahigh Temperature Alloy
摘要
Abstract
Directionally solidified specimens of Nb-Ti-Si based ultrahigh temperature alloy with the withdrawing rates of 2.5μm/s and 50μm/s were homogenized at 1250,1350℃ and 1400℃ for 50h,respectively.The constituent phases were Nbss,β(Nb,X)5Si3 and γ(Nb,X)5Si3.The needle-like precipitates of Cr2 (Nb,Ti) appeared in the specimens directionally solidified at the withdrawing rate of 2.5μm/s after homogenizing treatments,and its amount increased with the homogenizing temperatures.After homogenizing treatments,the straight boundaries and sharp edges of the primary hexagonal silicides became smooth,the fine silicides in the center of the eutectic cells became spheroidzed,and some silicide blocks in the eutectic cells broke into small ones.The transformation from β(Nb,X)5Si3 to α(Nb,X)5Si3 did not occur during the homogenizing treatments.After homogenizing treatments,the microhardness of the alloy increased remarkably,and its value first increased and then decreased with the increasing of the homogenizing temperatures.The maximum value of microhardness of the constitute phases occurred in the specimens homogenized at 1350℃ for 50h.关键词
均匀化热处理/Nb-Ti-Si基超高温合金/组织演变/定向凝固/显微硬度Key words
homogenizing treatment/ Nb-Ti-Si based ultrahigh temperature alloy/ microstructural evolution/directional solidification/microhardness分类
矿业与冶金引用本文复制引用
胡永强,郭喜平,郭海生..热处理对定向凝固Nb-Ti-Si基超高温合金组织及显微硬度的影响[J].材料工程,2013,(6):5-11,7.基金项目
国家自然科学基金资助项目(51071124) （51071124）
博士点基金资助项目(20096102110012) （20096102110012）
