In order to improve the hardness of the aluminum profile, maintain the stability of other mechanical properties, after extrusion molding to take out the aluminum profile, and then quenching to cool it, then the choice of coolant is very important, in the end is water or other oil coolant? You get a very different result.
If water is used to cool, as a result of aluminum metal elements is one of the chemical nature very lively, very easy to combine with the oxygen in air to generate alumina (Al ₂ O ₃), alumina and other impurities in the air or gases in chemical reaction, generate chemical product can make the aluminum surface color is yellow, causing surface defects, which affect the appearance of the aluminum quality.
If it is to use oil cooled by coolant lubricant properties of hot extrusion of aluminum profiles could oxidation, surface was covered in oily liquid coolant, form a uniform layer of protective film layer, make aluminum internal performance and appearance are extremely stable uniform color, won't cause or yellow color, but should pay attention to are not allowed to be contained in the coolant water.
