| Aluminum alloy die casting is widely used in all walks of life as a forming method to obtain high precision and high cross-section finish products.However,due to the rapid filling speed of aluminium alloy in the process of die casting,air entrainment is easy to occur,which will produce some void defects in the product,thus affecting the mechanical properties of the die casting.Cavity defect is closely related to cavity structure and die casting process parameters.Therefore,it is important to study the influence of cavity structure and die casting process parameters on cavity defect in castings.In this paper,the porosity of the sample was calculated,the size of holes in the cross section of the sample was measured.Combining with the filling flow process of aluminum alloy in the cavity,the dynamic forming process of cavity defects in die-casting aluminum alloy with different gate thickness and different injection velocity was comprehensively studied.The results are obtained:(1)With the increase of gate thickness,the overall trend of filling process of aluminium alloy has little difference,but the flow state in the local cavity is different.When the inner gate remains unchanged,the filling process of liquid metal in the cavity will be more disordered with the increase of injection velocity.(2)With the increase of the injection velocity,the influence of the thickness of the inner gate on the porosity of the sample is not obvious,but with the increase of the thickness of the inner gate,the influence of the injection velocity on the porosity of the sample increases first and then decreases.(3)With the increase of injection velocity,the total area of hole defects on the surface of S 2 and S 3 specimens with different inner gate thickness is the largest;with the increase of inner gate thickness,the influence of injection velocity on the total area of hole defects on the surface of specimens increases first and then decreases. |
PDF Full Text Request