Abstract
The master alloy ingot of Nb-Ti-Si based ultrahigh temperature alloy was prepared by vacuum nonconsumable arc melting. The coupons were homogenized at 1300, 1400, 1500 and 1600°C for 50 hours respectively, and then aged at 1100°C for 50 hours. The heat-treated microstructures were still composed of Nbss and (Nb, x)5Si3 (x represents Ti, Hf and Cr elements). But after the heat treatments both at 1600°C, 50 h and 1600°C, 50 h+1100°C, 50 h, HfO2 was found in the mucrostructure. With the increase of heat treatment temperatures, polygonal and plate-like big (Nb, x)5Si3 is desolved gradually or broken into small ones, and the amount of retained typical lamellar or rod eutectic colonies reduced gradually. 1500°C, 50 h+1100°C, 50 h is an optimum heat treatment process for Nb-Ti-Si based ultrahigh temperature alloy.
Original language | English |
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Pages (from-to) | 1601-1605 |
Number of pages | 5 |
Journal | Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering |
Volume | 37 |
Issue number | 9 |
State | Published - Sep 2008 |
Keywords
- Aging treatment
- Homogenizing treatment
- Microstructural evolution
- Nb-Ti-Si based ultrahigh temperature alloy