High pressure and high-speed filling die cast aluminum molds are two major characteristics of die cast aluminum. Its commonly used injection specific pressure ranges from thousands to tens of thousands of kPa, and even up to 2 × 105kPa。 The filling speed is about 10-50m/s, and sometimes it can even reach over 100m/s. The filling time is very short, usually within the 0.01~0.2s boundary.

advantage

1. Good product quality: The dimensional accuracy of castings is high, usually equivalent to levels 6-7, and even up to level 4; Good surface brightness, usually equivalent to 5-8 levels; The strength and hardness are relatively high, and the strength is usually increased by 25-30% compared to sand forging, but the elongation is reduced by about 70%; Stable size and good interchangeability; Die-casting aluminum thin-walled complex castings. For example, at this moment, zinc alloy die-casting aluminum parts can reach a minimum wall thickness of 0.3mm compared to small ones; Aluminum alloy castings can reach 0.5mm; The aperture of the control small casting is 0.7mm; The control small pitch is 0.75mm.

2. High production efficiency: High mechanical production rate. For example, the domestically produced J-III3 horizontal cold air die-casting aluminum machine can cast aluminum 600-700 times per eight hours, while the small hot chamber die-casting aluminum machine can cast aluminum 3000-7000 times per eight hours; Die-casting aluminum molds have a long lifespan, with a pair of die-casting aluminum molds and die-casting aluminum bell alloys, the lifespan can reach several hundred thousand times, even millions of times; Easy to achieve mechanization and automation.

3. Good economic efficiency: Due to the advantages of accurate size and bright surface of die-casting aluminum parts. Usually, it is used directly without mechanical processing, or the processing volume is very small, which not only increases the metal fraud rate but also reduces a large number of processing equipment and working hours; The value of castings is cheap; It is advisable to choose combination die-casting aluminum with other metal or non-metallic raw materials. It saves both working hours and metals.

shortcoming

1. Due to the high speed of liquid metal filling the mold cavity and unstable flow state during die casting of aluminum, the usual die casting aluminum method is chosen, which is prone to air holes in the casting and cannot be subjected to heat treatment;

2. For castings with complex concave cavities, die-casting aluminum is more troublesome

3. High melting point alloys (such as copper and black metals), die cast aluminum molds have a lower lifespan;

4. It is not suitable for small-scale production, as the key reason is the high cost of die-casting aluminum mold manufacturing, the high efficiency of die-casting aluminum machine production, and the uneconomical small-scale production.