Abstract:To fabricate tritium penetration barrier of aluminizing coating on Chinese low active martensite (CLAM) steel, electroplating of aluminum on CLAM steel from ambient temperature chloroaluminate ionic liquid AlCl3-MEIC（AlCl3-1-ethyl-3-methylimidazolium chloride） was carried out. The adhesion of substrates and aluminum coating at different pretreatment of the substrates was examined. The surface morphology,crystal size of aluminum coating at different current densities were examined by SEM and EDS. Comparing the surface morphology of aluminum plated by direct current process with which plated by pulse current process. The results show that the electroplating of aluminum on CLAM steel from AlCl3-MEIC is feasible. The current density of electrical pretreatment has influenced to the adhesion of substrates and aluminum coating. Increasing the current density can improve the adherence of substrates and aluminum coating. Using pulse current plating process can improve the compactness of surface morphology. Particle size of aluminum coating decreases with increasing current density. Spherical structure of aluminum coating increases with increasing current density. The deposited aluminum coating is whiter, smooth and uniform at preferable plating techniques. The preferable range of current density is 10～20 mA/cm2.The range of electroplating time is 45~95 min. The pulse current process is better.