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Effect of extrusion on 6063 aluminum wire rod
- 2019-10-08-

6063 aluminum alloy is widely used in decorative structures with its medium strength, good corrosion resistance, polishing, anodizing coloring and painting properties. At the same time, because of its good electrical and thermal conductivity, it is also widely used as a heat sink for computer CPUs. The extrusion ratio affects the microstructure of the alloy and the size of the main strengthening phase Mg2Si in the aluminum alloy. As the extrusion ratio increases, the grain size of the aluminum alloy decreases and the size of the strengthening phase Mg2Si decreases and the density increases. . As the extrusion ratio increases, the density of the strengthening phase in the aluminum alloy increases, and the distribution becomes more uniform, and the tensile strength, elongation and hardness of the aluminum alloy increase.

Since the main products of the 6063 aluminum alloy on the market are extruded profiles, it is crucial to select a suitable extrusion ratio to improve the performance of the product. This paper mainly analyzes the influence of extrusion ratio on the microstructure and mechanical properties of aluminum alloy, and provides a basis for improving the extrusion process of 6063 aluminum alloy and improving the product quality of the aluminum alloy.

The 6063 aluminum alloy is prepared from pure aluminum ingot, pure magnesium and Al-Si intermediate alloy, and the composition of the aluminum alloy is (mass fraction, %):

0.43Si, 0.001Cu, 0.701Mg, 0.005Zn, 0.071Ti, 0.17Fe, 0.001Mn, balance Al.

The smelted 6063 aluminum alloy solution was cast into a Φ120mm aluminum wire rod , and after homogenization treatment at 560 ° C × 6 h, the aluminum rod was heated to 460 ° C and placed on a 600 t extruder to be extruded into solid at different extrusion ratios. The round bar has an extrusion ratio of 32.7 (A), 39.05 (B), 49 (C), 59.55 (D), and 68.64 (E), respectively. After the extrusion, the obtained solid round bar was subjected to aging treatment at 200 ° C × 2 h.

The aluminum alloy round ingot is rolled on the ground. When there is sediment or dust on the surface, it should be cleaned and then heated into the furnace.

The temperature setting of the aluminum rod heating furnace is set at 300 °C-450 °C, and the temperature control of the aluminum rod on the machine, according to the wall thickness should be consistent with T≥1.4mm and the temperature is controlled at 440°C-540°C, T<1.4mm it="" is="" controlled="" at="" 400="" °c="" -="" 540="" °c,="" depending="" on="" the="" type,="" mold="" structure="" and="" alloy=""> The aluminum alloy round ingot should be self-examined before the furnace is heated. The self-inspection is responsible for the self-inspection. Any round ingot with obvious slag inclusion, cold separation, center crack and bending should not be heated into the furnace. It should be selected and returned to the casting shop. The furnace tube was heated to 380 ° C - 420 ° C by heating at a temperature of 100 ° C / 1 hour. The end surface temperature of the ingot tube is 280 °C---360 °C . The end surface of the ingot cylinder and the mold should be flat without damage and sticky aluminum, otherwise it will run when squeezed. During the extrusion process, the extrusion squad should measure the temperature with a portable thermometer every 10-20 ingots and record it as it is so as to keep track of the temperature change of the ingot and maintain the normal extrusion temperature. Pay attention to changes in pressure when squeezing. When the pressure is not more than 210kg/cm2, the pressure will decrease with the process during normal extrusion. If the pressure does not decrease after more than 1 minute after the pressure is applied, the extrusion should be stopped to prevent damage to the equipment and the mold. The extrusion speed should be controlled according to the different characteristics of different alloys. The extrusion speed of low impurity alloys can be higher, and the extrusion speed of high impurity alloys will be slower. If the aluminum rod temperature is too high, the extrusion speed should be reduced. If you want to increase the extrusion speed, the aluminum rod temperature should be controlled lower. In order to control the mechanical properties, the temperature of the discharge port must be ≥500 °C.