Process Research On Hot-extrusion-fine-blocking For A Typeof Armor Piercing’s Head

Head of shell is an important part of armour-piercing projectile, which production quality directly influences the hitting effect. Due to head of shell’s complex structure and high requirements of dimensional accuracy and mechanical properties, head of shell blanks must be produced with high quality. Currently, the production process of head of shell blanks uses bar forging, and mechanical processing the structure of the hollow which leads to material utilization less than 30%, a serious waste of raw materials, and poor economic efficiency of enterprises. This paper adopts the hot extrusion precision forming technology, extrudes head of shell blank with tube blanks, which has important significance for improving the utilization of materials.Based on the rigid-plastic finite element method, this thesis establishs the blank of head of shell in hot extrusion forming finite element analysis model. Though finite element analysis, the paper further confirms that the process scheme need respectively form head of shell blank tail and head useing closed-die extrusion and local heating.The paper analyzes the causes of hot extrusion head of head of shell blank folding defect, thinks that the dimensions of the tube affects the shaping effect.To further study the factors affecting the shape of the tube, the paper uses the tube blanks with different specifications, different process parameters, including the punch velocity, tube local heating temperatures and different friction factor to observe maximum forming load and shaping effect and confirms the reasonable parameters.According to the results of numerical simulations, this thesis designs the mould for the head of shell refined blank in the actual production, adopts Pb as the experimental material, designs a simple physical simulation experiments, conducts the experimental study, finally gets to meet the requirements of sample, and further proves the correctness of the results of the finite element analysisand the feasibility of the process scheme.