The Simulation Analysis On Antigravity Squeeze Casting And Heat Treatment Of Connecting Rod Based On AL-Cu Alloy

Squeeze casting (liquid pressing) is a new technology between die-casting and deform, it fill the mould under low velocity and the process of solidification under pressure till the cast could coagulate completely, it is very useful to produce high mechanical alloy casting which is complex and thick. The study on the simulation of squeeze casting is to optimize the parameters of squeeze technology and gate system, which is few in our country, and some special question of squeeze casting should be setting in simulation, so it can express the process of squeeze casting clearly.This paper uses the high strength AL-Cu alloy connecting rod of motor bike as research object, adopting the indirect squeeze casting simulate the anti-gravity squeeze casting and heat treatment of AL-Cu alloy, the main research contents and results are follows:(1) This article uses several cycles simulation to get the dynamic temperature of the mould, and use this temperature as the initial temperature of squeeze casting, it solve the question of inaccuracy of simulation because of the uniform temperature of mold, according to the character of squeeze casting to use the method of SCHEIL to extend the date base of materials;(2) Three ways of model established by PROE into the PROCAST are discussed, choosing a good mesh to improve the accuracy and speed of computing. Preliminary selecting the technical parameters and under these sets, establishing the simulate process of squeeze casting under punch. At the simulation of treatment in furnace, we mainly consider the effect of radiation to the residual stress of casting;(3) Analysis on the technical parameters of squeeze casting are discussed, especially for the loading time of pressure, keeping time of magnitude, from the results, we can know that the liquid-metal flow of squeeze casting is very stable, and the variation of temperature of mold is always under permission, and from the fill time, solidification time and solid fraction to check the technological parameters. According to the results to analyze the reason and location of shrinkage, and also two ways of changing the shape and location of gate system and local pressurization are put forward to remove the defects;(4) The temperature of casting when leave the mould is selected as the initial temperature. Setting magnitude of the coefficient of heat transfer to simulating the connecting rod under air and water cooling process by PROCAST, the velocity of water cooling is fast, the residual stress in the connecting rod become larger, but the increment is limited, it show that the thick and thin of connecting rod are fast cooling speed, but the both are simultaneous, cooling speed is not the main cause of residual stress but for the structure. Using the residual heat of casting to reheat, then cooling with furnace to decrease the residual stress. In this process, we mainly consider the effect of radiation to the residual stress of casting, and it get the expected results from of simulation.We get the optimal technical parameters through the above simulating and research: the pouring temperature is 700℃, the velocity of punch is 55mm/s, the magnitude of pressure is 100MPa, delayed time is 7s. The inner gate should be locate in the middle of connecting rod, the shape of inner gate is designed to the rectangular to change the fill speed and direction, the thick B is 30mm, the length L is 3.5mm, so is can solve the shrinkage because of lack of pressure.