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一、铝合金的变形 铝合金机械强度不太高而塑性较好(特别如变形铝合金),受到外力作用较易发生变形。在残余内应力作用下也会发生变形。金属晶体受力作用后晶格位错的位能增加,当它超过位错运动的激活能时,位错便沿某方向移动,金属就产生(微)塑性变形。铝合金制件内较大的残余内应力是由原材料和不适当的金加工、热处理所造成。由于残余内应力分布情况比较复杂,随着时间推移,它持久作用的结果,在零件某些薄弱环节产生永久性的微塑性变形,零件尺寸可能产生变化,影响了精度。铝合金制件加工发生变形的例子是比较多的,例如:
First, the deformation of aluminum alloy Mechanical strength is not too high and good plasticity (especially, such as deformation of aluminum), subject to external forces are more prone to deformation. In the residual stress will also be under the effect of deformation. The position of the lattice dislocation increases after the stress is exerted on the metal crystal. When it exceeds the activation energy of the dislocation movement, the dislocation moves in a certain direction and the metal will generate (micro) plastic deformation. Aluminum alloy parts larger residual stress is caused by raw materials and improper gold processing, heat treatment caused. As the distribution of residual stress is more complicated, as a result of its lasting effect over time, permanent micro-plastic deformation occurs in some weak parts of the part, the size of the part may be changed and the accuracy is affected. Aluminum alloy parts deformation is more examples, such as: