| A new electronic control box with a magnesium alloy was developed to achieve the purpose of lightweight. In this paper, the excellent performances of the new magnesium alloy (Mg-Al-Zn-1Ce-0.1Ti) was prepared by adding different amounts of Ce and Ti to Mg-Al-Zn based on orthogonal experiment on the use of conventional casting and the heat treatment process was designed. The mechanical properties, corrosion resistance and physical properties were studied by OM, SEM, XRD and coaxial flange tester.Mg-Al-Zn alloy was prepared by metal type casting method with α-Mg as the matrix, β (Mg17Al12) phase as the second phase. With the additions of Ce and Ti, the α-phase matrix was refined, the content of β-phase reduced and dispersed from continuous changes; Tiny needle Al4Ce phase and elemental Ti occurred in crystals; The mechanical properties research found that containing1.0wt.%Ce,0.1wt.%Ti cast Mg-Al-Zn alloy, the tensile strength reached189MPa, elongation rate reached10%, HB hardness reached72.6; The corrosion resistance research found that containing1.0wt.%Ce,0.1wt.%Ti cast Mg-Al-Zn alloy, corrosion resistance was improved. With16h immersion in NaCl3.5%wt solution, the corrosion depth was31.60μm.Mg-Al-Zn-Ce-Ti alloy was under solution treatment by413℃24hours, respectively at200℃and160℃aging6,10,12,14,16hours water quenched. The study found that solution treatment β (Mg17Al12) dispersed phase has dissolved, the base body of the aging process becomes more fine and Al4Ce phase concentrated in the grain boundary, so that β phase Al4Ce continuous phase precipitates around. And its mechanical properties after solution treatment and aging greatly improved after200℃aging12h, tensile strength up to213MPa, elongation rate increased to12.3%, compared with Mg-Al-Zn alloy tensile strength and elongation were increased36.5%and186%; β relative to the substrate a-Mg phase plays the role of the basis, so that the corrosion resistance was greatly improved, the corrosion rate significantly reduced, the corrosion potential of only1.466v, than Mg-Al-Zn alloy of17.6%improved.With Ce adding, the matrix was purified, smelting impurities reduced, electron scattering reduced and conductivity improved. Conductivity Mg-Al-Zn-Ce-Ti alloy generally Mg-Al-Zn-1Ce-0.1Ti alloy prepared in conductivity within range of0.9×10-2S/m-1×10-2S/m, representing excellent for1.015×10-2S/m. Electromagnetic shielding effectiveness by conducting research, and found to follow the relationship between the electromagnetic shielding effectiveness value (y) and frequency (x). |
