铝合金锻造开坯变形均匀性数值模拟与实验验证

Numerical simulation and experimental verification on deformation uniformity during forging-cogging process for aluminum alloy

锻造开坯变形均匀性是影响锻件质量的重要因素。以2A14铝合金为研究对象,利用Deform-3D有限元软件对锻坯应变场进行模拟,通过引入平均等效应变ε_(ave)、变形均匀系数a,结合晶粒形貌观察和拉伸力学性能测试,对“单向镦粗”和“多向镦粗”两种锻造开坯工艺的变形均匀性进行定量和定性分析。研究结果表明:“多向镦粗”锻造开坯工艺的变形均匀性较“单向镦粗”锻造开坯工艺好,且锻造累积应变量越大,变形均匀性越好,力学性能各向异性越弱。2A14铝合金在多向镦粗锻造开坯过程中,随着累积应变量的增加,晶粒细化机制由晶粒破碎机制逐渐转变为连续动态再结晶机制。

Deformation uniformity of forging-cogging is an important factor affecting the quality of forgings.Therefore,for 2A14 aluminum alloy,the strain field of forged-billet was simulated by finite element software Deform-3D.Then,by introducing average equivalent strain ε_(ave) and deformation uniformity coefficient a,combined with the observation of grain morphology and the tensile test of mechanical properties,the deformation uniformity of“unidirectional upsetting”and“multi-directional upsetting”forging-cogging processes were quantitatively and qualitatively analyzed.The results show that the deformation uniformity of the“multi-directional upsetting”forging-cogging process is better than that of the“unidirectional upsetting”forging-cogging process,and the larger the accumulated strain amount is,the better the deformation uniformity and the weaker the anisotropy of mechanical properties are.In the process of multi-directional upsetting forging-cogging process for 2A14 aluminum alloy,with the increasing of accumulated strain amount,the grain refinement mechanism gradually changes from the grain crushing mechanism to the continuous dynamic recrystallization mechanism.