铝硅合金轧制中硅晶粒应力集中数值模拟

The Numerical Simulation of Si Grain Stress Concentration in Al-Si Alloy Rolling

针对铝硅合金轧制过程中,不同形状硅晶粒对铝基体影响不明的问题.根据有限元方法,以球形和板片状硅晶粒为研究对象,建立了变质前后不同形状硅晶粒有限元模型,分析晶粒周围等效应力、等效应变云图及曲线.解决了普通实验只能以拉伸实验数据判定变质处理前后铝硅合金性能,而不能从材料内部应力、应变角度解读性能差异的问题.分析结果表明:板片状硅晶粒与球状硅晶粒相比,周围应变不均现象更加明显,等效应力值更大,对材料性能影响更加不利.证明了通过变质处理对铝硅合金性能提高的重要性.模拟结束后,通过对变质处理前后试样进行拉伸试验,间接验证数值模拟方法的可行性和模拟结果的正确性.

In the rolling process of aluminum-silicon alloy, there was a problem of silicon grains stress concentra- tion which results from the deformation resistance of silicon grain bigger than aluminum matrix. Aiming at this problem, we established the finite element model of reinforcement particles in rolling and researched the stress and strain contours and curves of silicon grains and aluminum body stress of reinforcement particles in rolling process can not through finite element procedures. The problem that the be analyzed quantitatively by ordinary experiment is also solved. The result shows that： the strain of the aluminum matrix near the grains is greater than other parts of the A1 matrix and far greater than the strain of silicon grain, which indicates the metal accumulation phenomenon appeared on the grains. The stress value of silicon grain is greater than aluminum matrix, which indicates stress concentration phenomenon appeared because of the accumulation of the metal near the grains. After the simulation, the feasibility of numerical simulation method and the accuracy of simulation results can be validated indirectly by the method of observing the feature of tensile fracture with the electron microscopy and the energy spectrum.