采用显微组织观察和JMatPro相平衡计算和热力学模拟软件等手段研究了一种实验Ni3Al基单晶高温合金的显微组织和1100℃/90 MPa条件下的持久高塑性变形行为,并分析了持久高塑性变形机制.实验Ni3Al基单晶合金为γ/γ'两相组织,热处理后合金枝晶干部位γ'相的体积分数为86.0％,其形貌呈接近立方体形.JMatPro软件在平衡相析出、γ/γ'相点阵常数和γ/γ'点阵错配度方面的计算结果与实验结果吻合的较好.合金1100℃/90 MPa的平均伸长率为148.5％,平均断面收缩率为72.3％.合金在持久变形过程中形成平行于应力轴方向的P型近似筏排组织使位错易于滑移传递从而在高温持久条件下表现出高塑性变形行为.
Microstructure,high plasticity deformation behavior and mechanism of an experimental Ni3Al-based single crystal superalloy under stress-rupture condition at 1100 ℃ and 90 MPa were investigated by microstructural observation and JMatPro numeric simulation.There are γ phase and γ' precipitates in the alloy.The volume fraction of nearly cubical γ' precipitates in the dendrite core of the alloy after heat treatment is 86.0％.The simulation results of equilibrium phase precipitation,lattice misfit of γand γ' phases as well as γ/γ'lattice misfit show good agreement with the experimental results.The average elongation percentage of the superalloy is 148.5％ and the average percentage reduction in area is 72.3％ at 1100 ℃ and 90 MPa.A P type nearly-rafted structure parallel to the stress axis forms during stress-rupture deformation.The dislocations can slip through freely and result in the high plasticity deformation behavior.
参考文献
| [1] | E. N. Kablov;B. S. Lomberg;V. P. Buntushkin.INTERMETALLIC Ni_3Al-BASE ALLOY: A PROMISING MATERIAL FOR TURBINE BLADES[J].Metal Science and Heat Treatment,20027/8(7/8):284-287. |
| [2] | 韩雅芳.Ni3Al及其合金的发展[J].航空材料学报,1990(01):53. |
| [3] | 李树索;郑运荣;韩雅芳;宋立国;苏喜孔.铝含量对定向凝固Ni3Al基合金显微组织和持久性能的影响[J].稀有金属材料与工程,2004(12):1329-1332. |
| [4] | 王建涛;韩伟;骆合力;李尚平.均匀化处理对MX246A合金组织和拉伸性能的影响[J].材料热处理学报,2014(4):162-165. |
| [5] | M. FAEHRMANN;P. FRATZL;O. PARIS;E. FAEHRMANN;WILLIAM C. JOHNSON.INFLUENCE OF COHERENCY STRESS ON MICROSTRUCTURAL EVOLUTION IN MODEL Ni-Al-Mo ALLOYS[J].Acta Metallurgica et Materialia,19953(3):1007-1022. |
| [6] | Fahrmann M;Fahrmann E;Boegli A;Pollock TM;Sockel HG;Hermann W.Determination of matrix and precipitate elastic constants in ( gamma - gamma ') Ni-base model alloys, and their relevance to rafting[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,19991/2(1/2):212-221. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%