Aluminum alloy wire with low density and high strength has been widely used. Aluminum alloy wire die casting technology is an advanced non-cutting technology, mainly applied to improve productivity, save raw materials, reduce production costs, improve product performance, improve precision and other industries, as well as advanced Al-Mg alloy products with high performance, high precision and high toughness.
1. Working conditions and performance requirements of Al-Mg alloy wire die casting die
Al-mg alloy die casting is a die for casting Al-Mg alloy castings on a die casting machine. Melting point of aluminum alloy 600~750℃ Melting point of magnesium alloy 600~ 700℃ During die casting, the working surface temperature of the die can usually rise to 500 ~ 600℃. The surface of the hollow, mandrel and nozzle are subject to violent temperature fluctuations, and the die surface is prone to thermal fatigue cracks. In addition, Al-Mg alloy is easy to stick to the die surface during die casting, which affects the continuous operation of die casting production. Liquid Al-Mg alloy has strong erosion on die surface.
⒉ Manufacturing process of aluminum-magnesium alloy wire die casting die
The manufacturing process of Al magnesium alloy die casting is as follows: blanking forging spherical annealing machine processing quenching, tempering repair, polishing, polishing nitriding (nitrogen carburizing) assembly and use.
3. Strengthening process of Al-Mg alloy die casting die
The strengthening treatment of Al-Mg alloy die casting is to change the microstructure of the steel to obtain the required microstructure and properties of the die. The heat treatment process specification should be determined according to the material, shape, size and complexity of the die.
3.1 Pre-heat treatment
Continuous annealing, isothermal annealing and tempering heat treatment can be used to preheat the die casting die, so as to obtain uniform structure and dispersed carbide before final heat treatment and improve the toughness of steel. The continuous degradation process is relatively simple and good granular pearlite structure can be obtained. For die casting die with complex shape and high demand, the ideal granular pearlite structure can be obtained by isothermal annealing.
3.2 Quenching Preheating
Die casting steel is mostly high alloy steel with poor thermal conductivity. Always take preheating measures when turning on lights. The number and temperature of preheating depends on the composition of die steel and the requirements of die deformation. For the mold with low quenching temperature, simple shape and low deformation requirements, it should be preheated once when heating, and there should be no crack. The high temperature quenching that needs deformation and the mold with complex shape need secondary preheating. This is to reduce the stress generated during the heating process, while making the overall mold structure uniform.