Efficiently-extrudable low-cost high-performance heat-conducting magnesium alloy and preparation method thereof

Abstract

The invention discloses an efficiently-extrudable low-cost high-performance heat-conducting magnesium alloy and a preparation method thereof. The magnesium alloy comprises the following chemical components by weight percent: 0.1%-0.8wt% of Al, 0.1%-0.6wt% of Ca, 0.1%-0.6wt% of Mn, 0.05%-0.4wt% of La and the balance of Mg and inevitable impurities. The density of the magnesium alloy is less than 1.78g / cm<3>, quick extrusion production at highest extrusion outlet speed of not less than 20m / min can be carried out, the room-temperature heat-conducting coefficients of final extrusion products are all more than 125W / (m*K), and the magnesium alloy is excellent in comprehensive mechanical property and can be applied to aerospace, computer, communication and consumer electronics, heat dissipation system structure materials of LED illumination products and structural member materials of medical, welfare and outdoor sports equipment.

Description

technical field [0001] The invention relates to a heat-conducting alloy and a preparation method thereof, in particular to a high-efficiency extrusion low-cost high-performance heat-conducting magnesium alloy and a preparation method thereof. Background technique [0002] Magnesium is the lightest of commonly used metal structural materials, with a specific gravity of about 1.74g / cm 3 , is 1 / 4 of steel and 2 / 3 of aluminum. Magnesium and magnesium alloys have the three advantages of rich resources, energy saving, and environmental friendliness, and are lightweight structural materials and functional materials with high specific strength. They are recognized by the world as "the most promising new materials in the 21st century" ". [0003] The thermal conductivity of pure magnesium at room temperature is high, about 157W / m*K, but the strength is too low, and the tensile yield strength in the cast state is about 21MPa. After pure magnesium is alloyed, its strength is signifi...

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Problems solved by technology

[0009] However, among Mg-Al-Zn alloys with low thermal conductivity, alloys with low Al content (such as AZ21, AZ31, etc.) can obtain a larger extrusion exit speed (≤20m / min), but after extrusion The room temperature tensile yield strength of the material is generally all lower than 150MPa (Japan Light Metal, 54pp.472-477 (2004), Chinese Patent Publication No. CN101805866B); although alloys with high Al content (such as AZ80, etc.) can obtain higher room temperature tensile Tensile yield strength (>200MPa), but its maximum extrusion exit speed is generally lower than 2m / min (Japan Light Metal, 54pp.472-477 (2004)), low production efficiency leads to high production cost of this series of magnesium alloys

Although patent CN101805866B discloses a kind of alloy that can carry out extruding speed to reach 15m / min, but this alloy contains noble metal Sr and rare earth element Ce, Y, and alloy cost is higher; , density 2.7g / cm 3 ) and Sb (antimony, density 6.7g / cm 3 ) element, resulting in a larger density of the alloy; and the invention does not involve the thermal conductivity and high-speed extrusion process of the magnesium alloy

The above-mentioned Chinese patents CN100513606C and CN101709418 design high thermal conductivity alloy components, due to the presence of second phase particles with a lower melting point (such as Mg-Zn phase), the alloy is very prone to surface cracking during extrusion and other processes, and it is difficult to achieve High Speed ​​Extrusion Processing

The low extrusion speed of magnesium alloy (generally ≤ 5m / min) is an important reason for the high price of magnesium alloy extrusion products, which seriously limits the large-scale application of magnesium alloy extrusion products.

[0010] In the existing disclosed magnesium alloy system, there is no magnesium alloy that can simultaneously take into account the three aspects of thermal conductivity, mechanical properties and production and processing properties.

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