Rare-Earth Element Ce Impact On The Framework And Performance Of LC4 Ultra-High Alnminum Alloy

The ultra-high strength aluminum alloy has many good characteristics, such as high strength, small specific gravity, high specific strength, high specific rigidity, nicer machining and welding performance, etc. It occupy a very important status in the aviation, spaceflight, military and civil industry especially in aircraft industry. It is one of the main structural materials of aircraft industry. LC4 ( 7A04 ) alloy is the most extensive kind of alloy using in the ultra-high strength aluminium alloy, it belongs to Al-Zn-Mg-Cu department. Being a kind of heat treatment intensifying deformation aluminium alloy, it has high comprehensive mechanical performance. Aiming at the development of LC4 (7A04) alloy and 7xxx series ultra-high strength aluminium alloys in our country ,the intensity and corrosion-resistant performance of LC4 alloy has been studied in this subject. The result of our study shows:(1) The joining of the rare-earth element Ce can make the crystalline grain of LC4 alloy get thinningly. At the same time, it can also improve the deformation processing characteristics of the alloy and improve plasticity.(2) Rare-earth element Ce can improve the comprehensive mechanics performance of LC4 alloy. When the content of Ce is 0.3%, on the basis of keeping the alloy's original high strength ,the prolongation quotiety of the alloy has been improved by about 20% than LC4 alloy not including the rare-earth element.(3) Rare-earth element Ce has beneficial function for raising the salt fog corrosion-resistant performance of LC4 alloy. The best additive quantity of Ce to improve the salt fog corrosion-resistant of LC4 alloy is 0.3%.