Research On Heat Treatment Process Of A354 Squeeze Casting Aluminum Alloy Fixed Clip

Heat treatment is an important means to improve the performance of aluminum alloy in the field of mechanical manufacturing.This study aims to explore a better heat treatment process of A354 aluminum fixed clips,thus shortening the production cycle and improving the mechanical.The influences of heat treatment on the microstructures and tensile properties of the part are investigated by lots of analyzing and testing methods such as OM,SEM,DSC and tensile testing.Besides,fluent software was used to simulate the temperature field and stream field in the heat treatment furnace.And find out the influence of the equipment and operation on the mechanical properties of the parts.The T6 heat treatment process of A354 aluminum alloy fixed clip is studied.It was found that when the solution temperature ranges from 490? to 515?,the longer the solid solution time in 0-6h,the higher the solution temperature is,the better the mechanical properties are;when it is between 515-525 ?,the holding time can be shortened within 3-4h.After the parts were soluted at 515? for 4h,the aging treatment was carried out at the temperature of 165?,175? and 185? respectively.It was clearly seen that the temperature is 185?,the hardening rate is faster.With the extension of aging time in 2-6h,the tensile strength increases but the elongation decreases gradually,the results show that the A354 aluminum alloys have good comprehensive mechanical properties when aging for 3 hours at 175±5?,which can meet the production needs.These experiments show the optimal process parameters for A354 aluminum fixed clip is: 515±5?×4h+175±5?×3h;and the tensile strength is 369 MPa,the elongation is 5.7%,the hardness is 130 HB,which can increase its hardness by 17.5%,tensile strength by 20.2% and elongation by 31.3%,and the production cycle is shortened by 3 hours,efficiency increased by 30%.After T6 heat treatment,the Si phases become grounder,the Mg and Cu dissolve in ?(Al)during the solution process,forming the super-saturated solid solution,then precipitating in the aging stage.The primary strengthening phases in the A354 aluminum alloy are Al2 Cu and Q phase.The fracture surfaces of the tension specimens are characteristic of the dimple,representing typical plastic fracture.Through sampling test from the heat treatment furnace,it was found that the quality of the products in different regions is unstable.Through the simulation results of Fluent software and the analysis of the process operation,the conclusions are as follows: the workpieces' stacking method and the furnace heating method have certain influence on the distribution of the temperature field.So the work piece density should be controlled in a reasonable way to ensure the smooth flow of gas in the furnace.