Optimization of Squeeze Casting Process of Mg-Al-Zn-Ti Alloy for Automobile Parts

Magnesium alloy has huge market potential in the field of automotive lightweight due to its advantages such as small specific gravity. But the formation of magnesium alloy has always been one of the technical problems that engineers and researchers want to solve. As a composite molding process, squeeze casting in Mg-A-Ca, Mg-9A|Zn, Mg-8A|-Zn, Mg-6Zn-0.1Ca

It has been applied to alloys such as 0.5Mn. People have studied the microstructure and mechanical properties of squeeze cast magnesium alloys [1-5]. However, magnesium alloys still have a long way to go in the commercial application of automobiles. The composition, forming and corrosion resistance of magnesium alloys all require further research. Alloying element T can effectively improve the corrosion resistance of metal materials. However, there are not many studies on the addition of alloying element T in magnesium alloy, and there are fewer studies on the squeeze casting of new Mg-A|-Zn alloys. For this reason, this paper uses different process parameters to carry out squeeze casting experiments on the new MgA-Zn alloy to optimize the squeeze casting process of the new MgA-Zn alloy. 1 Test materials and methods Use metal magnesium, aluminum, zinc, pure titanium and Mg-5Mn intermediate metal as raw materials to smelt the new Mg-A nTi alloy in an intermediate frequency induction melting furnace, and pour the molten alloy liquid into a self-made mold. The squeeze casting test of the new Mg-A|-ZnT alloy sample was carried out by a 2000kN horizontal die casting machine. The squeeze casting sample was a round rod with a diameter of 40mm and a length of 400mm. The chemical composition of the new MgA-Zn alloy is shown in Table 1. Metal Mn is added for impurity removal. The squeeze casting process parameters of the new magnesium alloy samples are shown in Table 2. Since extrusion pressure and pouring temperature are the two most important process parameters in the squeeze casting process, this article mainly studies the two process parameters of extrusion pressure and pouring temperature, and the pressure holding time 105 and mold temperature 250 during squeeze casting The temperature remains unchanged. Table 1 Chemical composition of the new type magnesium alloy (%) Tab1 Chemical composition of the new typemagnesium alloy (wt s%) Al Zn Ti Mn Fe Si Mg7.820450.300.230.0080.005 balance Table 2 New type magnesium alloy extrusion casting process Zn magnesium alloy can obtain excellent tensile properties. The new Tab2 Squeezing casting process of the new type Mg-A-ZnTi magnesium alloy is preferably 720°C. Figure 1 shows the tensile fracture morphology of the new sample 1680125MgA-Zn alloy sample 3 when the sample number pouring temperature/C extrusion pressure/MPa pouring temperature 720°C and extrusion pressure 125MPa. It can be seen from the sample 2700125 in Figure 1 that under the squeeze casting process parameters, the tensile fracture of the new sample 3720125MgA-ZnT alloy exhibits a relatively obvious toughness. The fracture characteristics of the sample 4740125 are distributed with more small toughness. Tear edge of the socket and a small amount of sample 5760125. The sample 672050, the sample 772075, the sample 8720100, the sample 97201, were cut by the wire cutting method to cut the tensile specimen and the enchanted test specimen. The tensile test piece is a round rod with an effective acid diameter of 10mm and a length of 85mm. The corrosion test sample is a disc with a diameter of 10mm and a thickness of 5mm. Tensile test of 10μm squeeze casting new MgA-ZnT alloy with WD-200D electronic method testing machine. Tensile fracture morphology of sample 3 Fg.1 Tensile fracture morphology of sample no.3 The speed is The 1mm/mn test was carried out at room temperature and the fracture of the tensile specimen was observed under the EVO18 scanning electron microscope under different casting temperatures of the new MgA-Zn alloy.