Study On Squeeze Casting Technique And Mold Design Of The Aluminum Alloy Bracket

That traditional casting method of producing aluminum alloy bracket has serious quality problems of little coMPact microstructure and is especially difficult for molding these supports. In this paper, liquid forging die technology was used to produce aluminum alloy bracket. In the aspects of mould filling process scheme, design of liquid forging die and process experiment, analysis of deficiency and so on, the liquid forging die technology and die design for producing brackets were studied.The results are as followings:Firstly, AlSi9Cu3alloy brackets were produced by indirect and direct squeeze casting for one part in each die. Then the adaptability and usability of the present small tonnage liquid forging equipment were estimated by some important technical parameters.Secondly, designs of forging die was established by considering designing of die forging for producing aluminum alloy bracket and the ability of production in the present small liquid forging equipment. The details were as follows: Composition of aluminum alloy brackets was one part of the entrance of pressure head. The forging die was equipped with2kNockout cylinder and3auxiliary side core-pulling cylinder and die blocks.Thirdly, the melted metal die forging experiment of AlSi9Cu3tensile test bars was did to study on mechanical properties and microstructure observation. In this process, orthogonal test were performed. Then the main technology parameters and the influence of each parameter on quality of the melted metal die forging were obtained. The results showed that the most influence factor on mechanical properties was the pressure, the influence of dwell time was less, and the filling speed had the least iMPact on the mechanical properties.Fourthly, the experiment for producing aluminum alloy brackets was performed according to the results of tensile bar. It was found that a completed aluminum alloy support could be produced under casting temperature750℃, liquid forging pressure ratio of75MPa, filling velocity30mm/s, the dwell time30s and preheating temperature280℃.Finally, different deficiency (such as cold shut, crack, porosity etc) occurred in the process of aluminum alloy bracket and tensile bar forging casting experiment. Then the reasons of these present defects were classified and studied on respectively. Some revised methods were established in order to optimize technology scheme.