The Basic Process Research Of Directly Plasma Forming Functional Gradient Materials

Direct plasma forming technology has a very wide using in fields of materials processing and manufacturing, and it has many advantages that traditional processing methods do not have. Such as plasma arc has a high energy density, good degree of cluster and to shape the more complex parts. The technology of directly plasma forming using in the forming of functional gradient materials method is a useful attempt to the forming method of functionally graded materials.This paper studies direct plasma forming process of functional graded material, and gets the optimical parameters of Fe-based super alloy,Ni-based super alloy and Al2O3 ceramic powder forming. DGZJ-T Fe-based super alloy and Al2O3 ceramic powder performs well when the current is 40A,Al2O3 volume ratio is 30%, the feed rate is 75mm/min. Direct forming of WF312 Fe-based super alloy and Al2O3 ceramic powder performs well when the current is 40A the feed rate is 210-300mm/min, mount of powder is 8g/min and the mount of gas is 0.3ml/s. Fe25super alloy and Al2O3 ceramic powder performs well when the current is 40A,the offset of Z-axis is 0.6-0.8mm, processing distance is 9mm, the speed of powder feeding is 8g/min and the feed rate is 300mm/min. Ni-based super alloy powder performs well when the current is 45A, the feed rate is 350-450mm/min, the speed of powder feeding is 8g/min and the mount of gas is 0.25ml/s. Then metallographic of samples is tested, and the experiments verify that the plasma direct forming of Fe-based super alloy,Ni-based super alloy and Al2O3 ceramic powder is feasible.The application of functionally gradient materials in mold design is discussed in this paper. The parameters from the analysis result by DYNAFORM of stamping forming to the mold automobile fender are as followed: The speed is 500mm/s, blank holder force is 1×10~4N, the dimension of drawing rib is 7.5mm high, the radius is 8mm, and fillet of convex and concave dies is 10mm. Meanwhile, the stress deformation on fender mold is analyzed by DEFORM to gain relative data of the deformation of convex and concave dies. The results show that the stress on punch is larger, and stress concentration occurs at the shape-changed part of edge, while the stress on die is smaller and results from the blank holder force.