%0 Journal Article
%T MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Nb-16Si-22Ti-2Hf-2Cr-2Al INGOT PREPARED BY VACUUM INDUCTION MELTING<br>真空感应熔炼Nb-16Si-22Ti-2Hf-2Cr-2Al合金的组织和性能
%A JIA Lina
%A GAO Ming
%A GE Jingru
%A ZHENG Lijing
%A SHA Jiangbo
%A ZHANG Hu School of Materials Science
%A Engineering
%A Beijing University of Aeronautics
%A Astronautics
%A Beijing
%A <br>贾丽娜
%A 高明
%A 盖京茹
%A 郑立静
%A 沙江波
%A 张虎
%J 金属学报
%D 2011
%I 
%X The melt with a nominal composition of Nb-16Si-22Ti-2Hf-2Cr-2Al was poured in a ceramic shell mould with a temperature gradient of about 4℃/mm, and the ingot with the dimension of 60 mm×170 mm was obtained. The relationship between the microstructure and mechanical properties was measured, and the effects of the silicide on fracture toughness at ambient temperature and compression strength at high temperature were analyzed. It is revealed that the microstructure of the alloy consists of Nb solid solution and silicides, and the cooling rate can obviously change primary phase and constituent phases. The volume fraction of Nb3Si formed at rapid cooling rate is significantly increased, and Nb5Si3 phase is formed with decreasing in cooling rate, whereas the volume fraction of the eutectic colonies and NbSS dendrites increase evidently, especially the second dendrite arm. Fine and uniform eutectic colonies are contributed to the ambient tensile strength, while the coarse primary Nb3Si decreases the tensile strength but improves the compression strength of the alloy. When the microstructure is mainly composed of fine (NbSS+Nb5Si3) eutectic colonies, the tensile strength and elongation of the alloy reach 449 MPa and 0.3%, respectively. When lath-like Nb3Si phase has 80 $\mu$m in width and 50% in volume fraction as well as its long axis is parallel to compression direction, the compression strength of the alloy at 1250℃ is about 650 MPa.
%K Nb-Si base alloy
%K vacuum induction melting
%K microstructure
%K tensile strength
%K high temperature compression strength<br>Nb-Si合金
%K 真空感应熔炼
%K 微观组织
%K 抗拉强度
%K 高温压缩
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=AB188D3B70B071C57EB64E395D864ECE&jid=B061E1135F1CBDEE96CD96C109FEAD65&aid=F64ADA4586991C9ECDB7A90456655398&yid=9377ED8094509821&vid=F4B561950EE1D31A&iid=CA4FD0336C81A37A&sid=7E8E8B150580E4AB&eid=BB0EA31DB1B01173&journal_id=0412-1961&journal_name=金属学报&referenced_num=0&reference_num=0