摘要
本文研究了Ｓｉ对Ｉｎ７１８合金凝固过程及元素偏析的影响。结果表明，当Ｓｉ含量升高后，不仅在枝晶或Ｌａｖｅｓ相中偏析程度加剧，而且在枝晶内的浓度也逐渐升高而达到显著水平。Ｓｉ降低Ｎｂ在Ｌａｖｅｓ相中的溶解度，因而促进Ｌａｖｅｓ相的析出，提高Ｌａｖｅｓ相吸收剩余液体的能力，缩小偏析区的面积。分析认为，过分降低Ｓｉ含量对改善合金凝固组织及提高终凝温度的作用不大。
The effect ofsi on the solidificatlon and segregation In Inconel 718alloy was studied.It was foundthat SI can be not only segregated In Laves phase greatly, but also dissolved Into the matrix notlceablywith the rise of St addition. The solubility of Nb in Laves phaes Is lowered by SI. Therefore, SI signlfl-cantly Increases the preclpltatlon ofLaves phase and reduces the segregated area. It Is useless to excessive-lydrop the SI content In order to ameliorate the solldlflcatlon mlcrostructure and to enhance the finishingsolidiflcatlon temperature.
出处
《航空材料学报》
CAS
CSCD
1996年第2期7-11,共5页
Journal of Aeronautical Materials
关键词
硅
高温合金
凝固
偏析
silicon,solidification,segregation,superalloy,inconel 718
