(1.哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院, 哈爾濱 150001;
2.北京航空材料研究所, 北京 100095)
摘 要: 采用新型的噴射沉積工藝制備了Al-2.15Li-1.28 Mg-1.26Cu-0.10Zr合金,對其不同時效狀態(tài)的拉伸性能及斷裂行為進(jìn)行了研究。實驗結(jié)果表明，噴射沉積Al-Li合金經(jīng)190 ℃、20 h 時效后達(dá)到峰時效狀 態(tài)，此時材料的綜合性能最優(yōu)(σb=528 MPa，σ0.2=420 MPa，延伸率為12%)。固溶淬火態(tài)實驗合金拉伸斷口為完全穿晶韌窩型。時效態(tài)合金的斷裂方式為穿晶和沿晶混合型。隨時效時間的延長，沿晶斷裂的比例增加。實驗合金沿晶斷裂的原因是位錯的共面滑移、晶界無析出區(qū)和晶界平衡相的析出。
關(guān)鍵字: 噴射沉積 快速凝固 Al-Li合金 顯微組織 拉伸性能
（1.College of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 ;
2.Beijing Institute of Aeronautical Materials, Beijing 100095）
Abstract:Al-2.15Li-1.28Mg-1.26Cu-0.10Zr alloy was prepared by spray deposition processing, and its tensile properties and fracture behaviour in various aging conditions were investigated. The spray deposited alloy reaches peak age condition after being aged at 190 ℃ for 20 h and obtains the best properties(σb=528 MPa, σ0.2=420 MPa , δ=12%). Fracture surface of the as-quenched alloy is totally dimple-transgranular type, while the failure mode of the aged alloy is a mixed type with intergranular and transgranular fracture. The volume of intergranular fracture increases with the aging time. The intergranular fracture is caused by planar slip of dislocations, the formation of PFZs and equilibrium phases along grain boundary.
Key words: spray deposition rapid solidification Al-Li alloy microstructure tensile property
