Brilliant achievements have been made in semisolid technology in theory and its industrial application is deepening gradually. On the basis of learning and summarizing the previous research, related research was carried out in combination with the semi-solid forming experiment I participated in in the laboratory. This study based on nanchang university cooperation with guangdong keda electrical and mechanical co., LTD. “in the semi-solid extrusion cavity key technology and equipment research and development” project and strategic emerging industry core technology research project of guangdong province and jiangxi province key laboratory of high performance precision forming, the basis of the research condition and research on semi-solid rheological forming technology and the main problems in technical foundation for research. Specific contents and expected objectives are as follows:
(1) Explore the connection of a special rheological squeeze casting molding equipment on the basis of laboratory LSPSF semi-solid pulping technology, and explore a “translation casting pressure solidification method” on the common pressure methods of squeeze casting (vertical pressure solidification method, inclined pressure solidification method, local pressure solidification method). A new type of vertical semi-solid extrusion casting machine was designed, developed and manufactured.
(2) the process of the forming process of A356 alloy in squeezing casting experiment, study the characteristics and mechanical properties, microstructure analysis of process parameters on microstructure and mechanical properties of the influence law, through the experiment of squeeze casting process, familiar with the various process parameters adjustment process, as well as the preliminary judgment of various process parameters on properties of squeeze casting parts, equipment and die debugging experience.
(3) The rheological extrusion casting process of 7075 wheel aluminum alloy was analyzed by numerical simulation, and the influence law of various process parameters on the performance of the parts was analyzed. The optimal process parameters were obtained through orthogonal experimental method to guide the experiment and production practice.
(4) Take aviation high strength forged aluminum alloy 7075 as an example to carry out the rheological extrusion casting forming experiment, design and develop the extrusion casting drawing and special die of the parts, and develop the special structure special die which is equipped with the special vertical extrusion casting machine and has the function of secondary inner cavity extrusion (forging). The microstructure and mechanical properties of 7075 alloy formed by rheological squeeze casting were studied. The influence of various process parameters on the microstructure and mechanical properties was analyzed. The solidification behavior and mechanism analysis of the remaining liquid phase of semi-solid slurry under high pressure and high cooling rate were studied.
(5) Heat treatment strengthening mechanism of aluminum alloy forged by rheo-extrusion casting. Taking 7075 alloy rheological squeeze casting parts as the research object, the optimal process parameters of T6 heat treatment were explored, the microstructure and comprehensive mechanical properties in the process of solid solution and aging treatment were studied and analyzed, and the precipitation strengthening mechanism and tensile fracture mechanism of heat treatment were analyzed.
