The Behavior Of Forging Technology And Compression Deformation Of Casting ZK60 Magnesium Alloy

At the present time, the researches on ZK60 magnesium alloys were focused on the grain refinement, superplasticity and composite material. It was less to study the casting ZK60 magnesium alloy's deformation. In the present paper, the effects of annealing treatment on the microstructures and properties of ZK60 Mg alloy were investigated. At the same time, the hot deformation behaviors of the present alloy were also studied by uniaxial and multi-directional compression tests.(1) The casting ZK60 magnesium alloy's plastic property study fore and after solution treatment.During the forging, the casting ZK60 magnesium alloys were easy to make intergranular crack. Through the annealing at 330℃for 16h, the grain boundary was fined and the mechanical property was improved. The elongation percentage and upset limit were changed from 5.5% and 60% to 8.2% and 85%. Fractography demonstrates that the as-cast alloys'tensile fracture consist of quasi-cleavage fracture mixed a little shear fracture and the alloys'tensile fracture mode after homogenizing is changed from intergranular fracture to transgranular fracture. In the upsetting tests, Metallographic microscopy (OM) and scanning electron microscope (SEM) were used to investigate the initiation of the microcracks in as-cast alloys and the intermetallic compound MgZn2 or Mg7Zn3 is the source of microcracks and would reduce the formability of alloy during its plastic deformation process. After solution treatment, because improved ZK60 magnesium alloys plastic deformation degree, it can get more dynamic recrystallization. All of this made the casting ZK60 magnesium alloys can deform directly.(2) Uniaxial compression tests of as-annealed ZK60 Mg alloyThrough changing the deform speed, temperature, strain capacity and deform pass, it was find that the annealed ZK60 expressed obvious hot work ability characteristic, but the temperature rise was high. Uniaxial compression with more steps was carried out up to large cumulative strains and get fine grained structure.(3) Uniaxial compression tests of as-annealed ZK60 Mg alloy...