Aluminum alloys and pure aluminum can be identified by the following methods:
1. Look at the hardness. Use a knife to scratch a few times on aluminum alloy and pure aluminum, and the flower is obviously pure aluminum. Because aluminum alloy has been heat-processed, it has higher strength, while pure aluminum is softer.
2. Use an instrument to detect the composition. Such as spectroscopy, SEM, fluorescence, etc. Aluminum alloys contain elements such as iron, copper, manganese, and magnesium, while pure aluminum is a pure substance with only aluminum elements.
3. Quenching treatment after heating. Observe the surface color after quenching, the discoloration is obvious, the gray or black is aluminum alloy, because of the existence of Cu element.
Industrial pure aluminum is generally defined as aluminum with a purity of 99.0% to 99.9%, and in China it is defined as aluminum with a purity of 98.8% to 99.7%. There are many grades of pure aluminum in China’s plastic deformation processing industry, and the main impurities in pure aluminum include iron and silicon. Pure aluminum is divided into smelting products and pressure processed products. The former is expressed by the chemical composition Al (aluminum, industrial use). Aluminum alloy is the most widely used non-ferrous metal structural material in industry, and has been widely used in aviation, aerospace, automobile, machinery manufacturing, shipbuilding and chemical industry. With the rapid development of industrial economy, the demand for welded structural parts of aluminum alloy is increasing day by day, so that the research on weldability of aluminum alloy is also in-depth. Aluminum alloy is currently the most widely used alloy.