Large diameter aluminum using air cooling and water cooling quenching
large diameter aluminum using air cooling and water cooling quenching of large diameter aluminum quenching from different high temperature suddenly dropped to low temperature for hardening, such as steel knife blade to quenching in water, only hard and sharp, and aluminum quenching both water quenching, air cooling quenching. After building 6063 aluminum box air cooling quenching, quenching of aluminum on aging furnace limitation within a certain time, crystalline arrangement of a aluminum, obviously improve the mechanical strength. In all metal alloy, but only the large diameter aluminum aging state. Large diameter aluminum extrusion profile forming temperature is 460 ~ 500 degrees, general requirements after quenching temperature for 200. Through the high temperature extrusion, after solution heat treatment ( Quenching) To carry on the artificial aging status of air cooling ( T5) ; By high temperature cooling extrusion process, and then makes artificial aging status of water-cooled ( T6) 。 Air-cooled, T5 is forcing the T6 is water-cooled after extrusion, after water quenching hardness is increased. But aluminum need bent, try not to T6 state, some people think that the difference between the T5 and T6 is only part of the cooling speed difference, not the difference between air-cooled water-cooled. Air cooling of the cooling rate is enough big, also can achieve T6 effect, on the contrary, but water cooling speed is not enough only is the effect of T5. Actually T6 state can be either online quenching ( Water cooled or air cooled) Lu: xingcai, can also be offline quenching ( With quenching furnace quenching) , but according to customer requirements and product specifications. In actual production, either the key is to achieve production process of the extrusion product mechanical strength requirement. Hardness with water cooling and air cooling speed has little to do. The better cooling effect after aging hardness will be better, why has the branch of T5 and T6, because T5 air-cooled product size will not deformation, such as almost all the doors and Windows profile can choose T5, and T6 material is water-cooled thickness thin profile will deformation under the influence of water, especially with deformation opening is easy to find water. Of course you can also use wave the form of the water to water, is the kind of water spray. The effect of the product after water will, of course, is much better than air cooling effect. Using semi-continuous direct water-cooling casting method. Direct water cooling method of cooling intensity big, cooling speed, thus refine casting organization, increase the density of tissue and thus improve the mechanical properties and heat treatment effect of ingot casting. Controlling casting temperature is 710 - 730 ℃, 50 - casting speed 70 mm/min, the cooling water pressure 0. 1 - 0. 3MPa。 In order to reduce the hot cracking tendency, and improve the chemical composition of alloy, using online add aluminum titanium boron fiber, add speed is 1700 - 2000mm/min。 In order to reduce and eliminate the coring of ingot casting, improve its chemical composition and organization structure of the inhomogeneity, aluminum casting rods for the homogenization treatment. Control of technical conditions is to cast bar heating to 540 - 8-550 ℃, the heat preservation 10 h, from strong wind cooling and water cooling. Should speed up the cooling after homogenizing annealing, in order to guarantee the uniformity of colour and lustre after anodic oxidation coloring.