Die Casting alloy
die-casting alloy should have the casting characteristics as follows:
(1) casting strain less.
(2) good fluidity and filling ability.
(a) Solidification time is short.
(b) low melting point or solidus temperature.
(c) the flow length of the melt in the mold.
(d) the solidus temperature of the solid fraction is small.
(e) surface tension and viscosity.
(3) adhesion with the metal mold.
(a) and the chemical affinity of iron.
(b) the melt is not easy oxidation.
(4) thermal cracking.
(a) thermal expansion coefficient is small.
(b) solid fraction.
(c) high-temperature strength.
(5) riser complement large, small solidification shrinkage.
die-casting alloy types of
die-casting alloys are the following:
(1) magnesium alloy
(2) aluminum alloy
(3) zinc alloy
(4) the high melting point of copper alloy
(5) of tin, lead the Department of the low melting point alloy
Die Casting Alloy material properties
(1) adhesion with the metal mold.
(2) light weight.
(3) low price, and price stability.
(4) good machinability.
(5) The corrosion resistance is good.
(6) good mechanical properties.
(7) good dimensional accuracy and dimensional stability.
(8) surface treatment characteristics of good.
(9) the excellent physical properties.
Die-casting aluminum alloy heat treatment
To change the properties of the heating and cooling processes can be considered is the heat treatment, but not every
aluminum units are required heat treatment, such as the cast that is able to meet the performance requirements or can not be heat treatment, especially die-casting
parts, heat treatment will produce blistering, generally can not be heat treated.
Die-casting aluminum alloy type and chemical composition of
common ADC1 die-casting aluminum alloy commonly referred to as Al-Si alloy, applicable to large, meat thin and shape of complex products containing Si element casting molten fluidity changed for the better. Poor heat between brittle and prone to brittle phase, while the corrosion resistance, high thermal conductivity, thermal expansion and a small proportion (2.65)
The ADC3 aluminum alloy is to add alloying elements such as Mg, Fe, Al-Si alloys with excellent mechanical properties, corrosion resistance, good castability, easy to mount with the metal mold when the Fe content less than 1.0 percent, the Ministry is the widespread use alloys. Another a common ADC5 and ADC6 alloy, also known as aluminum magnesium alloy, the solidification shrinkage received the order of thermal expansion coefficient, such a poor alloy casting, and good corrosion resistance, grinding loss of metallic luster. Suitable for anodic oxidation treatment, the impurities Fe, Si, etc. will affect the appearance of the decoration.
ADC12 alloy systems Cu alloying elements added in the Al-Si alloy is widely used representation of die-casting aluminum alloy casting and excellent mechanical properties.
alloying elements of aluminum alloy :
die-casting aluminum alloy generally aluminum silicon alloy, the following briefing composition and impurities on the aluminum alloy:
Si element
is the principal component of the die-casting alloys, but also significantly improved the mobility of the main ingredients from the eutectic to eutectic section with good mobility, but the precipitation of the Si content cutting poor. In addition, with increasing Si content, the tensile strength and hardness will increase. But the elongation decreased.
Cu element
aluminum solid solution of copper content, so that the mechanical properties change maximum intensity in 4-6% of copper content. Cutting is also good. But copper die-casting aluminum alloy would affect its corrosion performance.
Mg element
ADC5 ADC6 corrosion resistance of Mg-containing element alloy. Al-Mg alloy solidification range, so prone to hot brittleness phenomenon. In some alloy magnesium as impurities such as Al-Cu-Si system will generate a brittle Mg 2 Si, and therefore that the amount should be less than 0.3%, the United States are strict rules in 0.1 % or less.
Fe element
iron is easy to form the folder impurities needle of FeAl 3 harmful precipitation precipitation, but due to the cooling rate of die-casting soon, casting organizations detailed the impact of impurities is less sensitive. General die casting components containing about 0.7% iron, to avoid the phenomenon of adhesion by the metal mold. But it is best to control its composition below the range of 0.8 to 1.0%, to avoid large amounts of Fe intermetallic compounds caused by casting hard.
Ni element
and copper, the more increased with increasing aluminum content, the tensile strength, hardness, corrosion resistance variation can improve the high temperature tensile strength.
Mn element
added to the copper silicon aluminum alloy to improve its high temperature strength, but excessive, will be of Al-Si-Fe - Mn of the quaternary compounds generated, leading to hard points on the casting. Al-3% Mn alloy flowability, suitable to be corrosion resistant products.
Zn element
Zinc is the reason for the high-temperature brittleness, and JIS provisions required in 1.0%, and foreign regulations to add the amount required to allow less than 3%. When the addition is kept below 1.0%, die casting, less likely to cracking phenomenon.