Aluminum alloy has a wide range of applications and is very common. Now everyone in the society contacts aluminum alloy at all times, such as mobile phone shell, mobile phone parts, computer game keyboard, aluminum for lighting lamps, rice cooker, electric kettle. Insulation Cup, aluminum alloy doors and windows, closing ladder, bracket, etc. In particular, almost everyone has one communication tool, and some even have two or three or more. There are aluminum, titanium and magnesium. The titanium body is bright and strong, but its price is high and its density is 66.7% higher than that of aluminum; the density of magnesium is small, 36% lighter than that of aluminum, and it has a silver shining color, but its strength is lower than that of aluminum, and its corrosion resistance is far lower than that of aluminum, and its price is higher than that of aluminum; therefore, aluminum is currently the best comprehensive performance and cost-effective smart phone body material, and its recyclable. The properties and recyclability are also better than those of titanium and magnesium. The aluminum, magnesium and titanium mentioned here contain various alloys.