One. Advantages of die-cast
1. High production efficiency, the production process easily mechanized and automated. Usually cold chamber die-casting machine per hour from 50 to 90 times, while the hot chamber die-casting machine per hour from 400 to 900 times, high production efficiency.
2. The casting a high dimensional accuracy and high surface quality. General casting tolerance levels for the GB / T1800-2009 IT13 ~ IT15, high accuracy can be achieved IT10 ~ W11. The surface roughness of 3.2 to 1.6 feet mouth bucket m, locally up to 0.8 bucket m. Because of high precision casting size and high surface quality, less demanding die castings can be used directly, avoiding machining or less by machining, improve the utilization of the alloy, save a lot of machining costs.
3. The high mechanical properties of die casting. Die-casting of molten metal in the cooling speed, and crystallization under pressure, so casting near the surface layer of finer grain, dense. High strength and hardness.
4. Die-casting complex thin-walled parts. Casting parts with complex shapes can, while the wall thickness of the part may be small, the minimum wall thickness of aluminum die casting is 0.5mm, zinc alloy die casting minimum wall thickness up to 0.3mm.
5. The casting of other materials can be embedded in the cast parts. This can save valuable material and processing costs, and can get parts of complex shape and improve part performance, reduce assembly effort.
II. Die Casting shortcomings
1. Die Castings prone to porosity. Since the molten metal at a very high speed filling of the mold cavity die casting, and mold material and no air permeability, general casting process for the production of die castings prone to porosity. Due to the presence of pores makes casting method can not by heat treatment to improve the strength and the use at high temperatures; and parts of allowance is not too large, otherwise it will remove the casting surface of the hardened layer, so that the exposed surface of the pores near the casting surface.
2. suitable for small batch production. Die-casting complex, high cost, it is generally only suitable for large volume production.
3. The die-casting die life is low melting point alloy. Some metals (such as copper alloy) high melting point, high thermal deformation of die-type material and the thermal fatigue strength requirements, lifetime use of molds relatively low. Currently casting material mainly aluminum, zinc alloys and magnesium alloys, ferrous metal die-casting processing methods are rarely used.