AZ31镁合金流变成形制品裂纹的形成原因

Origination of Crack Formation in the AZ31 Magnesium Alloy Rheoforming Products

镁合金的塑性成形性能差,因此如何实现镁合金的塑性加工成形成为了一个新的技术难题。连续流变挤压成形实现了镁合金由高温液态直接形成制品的过程,减少了工序,节约了能源。但是制品的上下表面易出现裂纹,出现裂纹的原因主要是金属流动速度不同。为了减小和消除裂纹,可采用润滑剂、控制挤压速度、增大模具的定径带长度等措施。

Magnesium alloy exhibits poor plastic performance,therefore,the plastic forming of magnesium alloys becomes a new technical challenge.Continuous rheo-extrusion forming realizes magnesium alloy from high-temperature liquid directly into finished products,reducing procedures and saving energy.However,there often appears cracks on the upper and lower surfaces of the products.Origination of crack formation was analyzed.The different liquid metal velocity is responsible for the crack formation in the alloy products.Through using lubricant agent,controlling extruding rate and enlarging fixed-radial length of the mould,the crack is eliminated.