分析了Nb-Ti-Cr-Si基超高温合金有坩埚整体定向凝固试样不同区域的组织,结果表明未熔区的组织由初生相Nbss、块状的(Nb,X)5Si3和少量的小块状Cr2Nb组成.在过渡区初生相Nbss依附在未熔区的Nbss优先生长,Nbss/(Nb,X)5 Si3共晶组织生长比较混乱,在初生相Nbss枝晶间出现了富Ti的Nbss/Cr2 Nb共晶团.稳态区组织中Nbss和(Nb,X)5Si3定向排列,实现了整体定向凝固.固/液界面形态为树枝状,在糊状区出现了Nbss/(Nb,X)5Si3、富Ti的Nbss/(Nb,X)5Si3和Nbss/Cr2 Nb三种共晶组织,根据组织分析的结果并总结了其凝固路径,测试了不同区域组织的显微硬度,结果表明稳态区的(Nb,X)5Si3的显微硬度最高.
参考文献
| [1] | Bewlay B P;Jackson M R;Subramanian P R .Processing of high-temperature refractory metal silicide in situ composites[J].JOM,1999,51(04):32. |
| [2] | Mendiratta M G;Dimiduk D M .Microstructures and mechanical behavior of two-phase niobium silicide-niobium alloys[J].Materials Research Society Symposium Proceedings,1989,133:441. |
| [3] | Tang Liang,Ma Chaoli,Zhao Xinqing.Effect of Cr on Microstructure and Fracture Toughness of Nb-20Ti-16Si-xCr Alloys[J].稀有金属材料与工程,2009(z3):8-12. |
| [4] | Sha J B;Liu J;Zhou C .Effect of Cr additions on toughness,strength,and oxidation resistance of an Nb-4Si-20Ti6Hf alloy at room and/or high temperatures[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,2011,42A:1514. |
| [5] | Guo Xiping;Guan Ping;Ding Xu et al.Microstructure and mechanical properties of an advanced Niobium based ultrahigh temperature alloy[J].Materials Science Forum,2006,539-543:3690. |
| [6] | Guo Xiping;Guan Ping;Ding Xu et al.Unidirectional solidification of a Nbss/(Nb,X) 5 Si3 in-situ composite[J].Materials Science Forum,2005,475-479:745. |
| [7] | Geng Jie;Shao G S;Tsakiropoulos P .Study of three-phase equilibrium in the Nb-rich corner of Nb-Si-Cr system[J].INTERMETALLICS,2006,14:832. |
| [8] | J. Sha;C. Yang and J. Liu .Toughening and strengthening behavior of an Nb-8Si-20Ti-6Hf alloy with addition of Cr[J].Scripta materialia,2010(11):859-862. |
| [9] | Y. Yang;B. P. Bewlay;Y. A. Chang .Liquid-Solid Phase Equilibria in Metal-Rich Nb-Ti-Hf-Si Alloys[J].Journal of Phase Equilibria and Diffusion,2007(1):107-114. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%