1420Al-Li合金模锻件热处理新工艺及机理

New Heat Treatment Process for 1420 Al-Li Alloy Die-Forging and Mechanism

采用正交法设计了 14 2 0Al-Li合金模锻件的热处理工艺方案 ,按设计方案进行了热处理试验和力学性能测试 ,并运用金相、透射电镜等手段研究了固溶温度、固溶时间、时效温度、时效时间影响14 2 0Al-Li合金模锻件强度和韧性的微观机制 ,获得了 14 2 0Al-Li合金模锻件的最佳热处理工艺制度。结果表明 :合金经 4 5 5℃× 170min固溶淬火 ,14 0℃× 12～ 16h时效工艺处理后 ,力学性能指标分别为σb≥ 4 93MPa ,σ0 .2 ≥ 398MPa ,σ≥ 12 9% ,达到最佳的强韧性效果。同时 。

The plan of heat treatment processes for 1420 Al-Li alloy die forging is designed using the orthogonal method. The heat treatment experiments are made and the mechanical preperties are tested according to the designed plan. The effect of solid solution temperature, solid solution time, ageing temperature, ageing time on microscopic mechanism of the mechanical properties of the 1420 Al-Li alloy is investigated using microscope and TEM.The best heat treatment precess of the 1420 Al-Li alloy is obtained. The experimental results indicate that the strength σ b,yield stress σ 0.2 , percentage elongation δ of the alloy reach separately 493 MPa, 398 MPa, 12.9% adopting 455 ℃×170 min quenching, 140 ℃×12～16 h ageing. The mechanism of the high strength and toughness is also discussed.