Structure and properties on surface of aluminizing-modification magnesium alloy in rolling

A new method of surface modification, "solid diffusion + rolling" was introduced, which means on the basis of studying surface modification method and technology of magnesium alloy sheet, solid diffusion method was applied to perform surface aluminizing-modification on AZ31 magnesium alloy sheet and obtain the Al/AZ31 magnesium matrix composite and by aid of finite element software LS-DYNA to simulate the cold rolling process to obtain optimum rolling technology conditions and rolling tests were performed. By means of the following appliances to test surface organization performance of material: XRD, SEM, metallographic microscope, Brinell hardness tester, reciprocating friction & wear tester and CorrTest corrosion electro-chemistry test system. The result indicates that the grain of Al/AZ31 magnesium matrix composite surface organization becomes much tinier and even due to surface deformation strengthening after rolling deformation, and a new phase MgAl₂O₄ is produced simultaneously making abrasion and corrosion resistance better which are manifested in surface Brinell hardness improving from HB61.4 to HB63.5, friction coefficient improving from 0.52 to 0.60, surface friction wear mass loss decreasing from 0.33 mg to 0.26 mg, self corrosion potential improving from -1.49 V to -1.38 V (surface corrosion resistance is improved significantly) and current density for self corrosion decreasing from 6.2×10^-3 mA/cm² to 7.0×10^-4 mA/cm². Abrasion resistance for Al/AZ31 magnesium matrix composite through "solid diffusion + rolling" is getting better as well as corrosion resistance.