利用外约束型模拟空间热循环温度场试验设备对1420Al-Li合金焊缝进行了热循环(77～393 K)试验,测量了热循环前后焊缝的拉伸性能,并观察了热循环前后焊缝的显微组织,讨论了热循环对焊缝组织和拉伸性能的影响.试验结果表明,经1000次或3000次热循环后,焊缝的强度和延伸率显著降低.热应力使焊缝显微组织产生损伤,主要表现为从晶界处向晶内发射位错,在晶界处形成位错塞积群,晶粒内位错密度逐渐升高.随着热循环次数的增加,组织损伤的不断累积导致在晶界处产生的应力集中程度增大,这是导致合金焊缝强度和延伸率下降的主要原因.
参考文献
| [1] | Wang Yajun;Mao Zhiyong;Bai shaojun.Mechanical properties of 1420 Al-Li alloy welds by EB welding[J].Aeronautical Manufacturing Technology,1998(06):12. |
| [2] | Deng Jixiong;Li Yan;Zhang Wenyang.Effects of pores on mechanical properties in welding joints of 1420 Al-Li alloy[J].Journal of Materials Engineering,1998(11):24. |
| [3] | Bratukhin A G;Densisov B S;Sotnikov V S.Technological problems of the 1420 Al-Li alloy aircraft structure with use of welding[J].Journal of Materials Engineering,1997(02):38. |
| [4] | 吴运学;王晓薇.碳化硅/铝复合材料热循环损伤的初步研究[J].宇航材料工艺,1992(04):62. |
| [5] | 盛磊.航天飞行器对树脂基复合材料的期望[J].宇航材料工艺,1992(04):27. |
| [6] | Le Flour J C;Locicero R .Influence of internal stresses induced by thermal cycling on the plastic deformation resistance of an Al/SiC composite material[J].Scripta Metallurgica et Materialia,1987,21(08):1071. |
| [7] | Siegmund T;Werner E;Fischer F D .Irreversible deformation of a duplex stainless steel under thermal cycling[J].Materials Science and Engineering A,1993,169(1-2):125. |
| [8] | Daehn G S;Oyama T .The mechanism of thermal cycling enhanced deformation in whisker-reinforced composites[J].Scripta Metallurgica et Materialia,1988,22(07):1097. |
| [9] | Ratna V;Sarma D S .Influence of thermal fatigue on the microstructure of a Ni-base superalloy[J].Scripta Metallurgica et Materialia,1993,29(04):467. |
| [10] | Tsuji K;Takegawa Y;Kojima K .Thermal fatigue characteristics of Ni-Ti-Cu alloy coils[J].Materials Science and Engineering,1991,136:1. |
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%