The design of die casting of aluminum alloy affects the yield
Aluminum alloy die casting features are obvious, aluminum liquid cooling speed is fast, aluminum alloy die casting has a strong chilling effect, casting grain refinement, dense organization, high comprehensive mechanical properties, accurate size, smooth surface, quality has been improved, affecting the quality of the uncertain factors have been reduced, especially suitable for mass production, good structure, It can minimize the processing allowance and the size of the rising, and the process production rate and blank utilization rate are improved compared with other die casting, so that the cost of the casting is relatively reduced, aluminum alloy with its flexibility, versatility and low cost still has a specific advantage, occupies a certain position.
Aluminum alloy die-castingIt has obvious characteristics. The aluminum liquid has a fast cooling speed, which has a strong chilling effect on aluminum alloy die-casting castings. The castings have fine grains, dense structures, high comprehensive mechanical properties, accurate dimensions, smooth surfaces, and improved quality. The uncertainties affecting the quality of castings have been reduced. It is especially suitable for mass production, with good structure, The processing allowance and riser size can be minimized, and the process yield and blank utilization rate are improved compared with other die-casting, so that the cost of castings is relatively reduced. Aluminum alloy still has specific advantages and occupies a certain position due to its flexibility, versatility and low cost p>
The aluminum alloy has large thermal conductivity and small volumetric heat capacity. The temperature of the molten metal will drop rapidly during the flow process. The liquid aluminum is active, and it is very easy to absorb air and oxidize. If the oxide film formed on the surface is always complete during casting, it can protect the aluminum liquid below and prevent secondary oxidation. If the casting is unstable or not stable enough, the oxide film breaks, and the oxide slag on the surface is drawn into the aluminum liquid below, it is difficult to float to the surface again, and all kinds of gases are not easy to separate out. Because the density of aluminum and aluminum oxide is similar, resulting in slag inclusion in the casting, large shrinkage rate, and easy to appear shrinkage cavity, porosity, pinhole, slag inclusion and other casting defects. Therefore, the smooth casting of aluminum alloy die castings is particularly important p>
In actual production, it is difficult to organically combine the advantages of the traditional metal mold gravity casting gating system. If we focus on the stability of mold filling (bottom injection), we cannot obtain a reasonable cavity heat distribution. Focusing on reasonable heat distribution in the mold cavity (top pouring), the casting stability will be lost. Therefore, the traditional metal mold gravity casting process has caused a negative situation of low process yield and low blank utilization rate for a long time p>
Smooth filling, full feeding and reasonable condensation sequence are the key problems to be solved in the design of gating system p>