Application Of Microarc Oxidation Technology On Al-Based Rapid Tooling

Micro—arc Oxidation technology is a new surface treatment technology. Excellent cerament coating can be achieved when the new technology is applied on the surface treatment of aluminum , magnesium, Titanium etc..The dissertation focuses on the surface strengthening of the die and mold by MAO coating. On the base of parameters optimization of the MAO coating, MAO coating with well-capability is obtained successfully. X-ray diffraction method(XRD), Scanning electron microscopy (SEM), NEPHOT-32 optical microscopy and HVS-1000 microhard tester were used to investigate the microstructure,hardness and morphology of MAO coatingThe phase composition and microstructure and thickness of the MAO coatings were investingated by XRD and SEM analyses, and the hardness is measured with microsclerometer . It was found that MAO coatings with a hardness of up to 2400 HV and with excellent wear resistance . MAO films have high hardness and excellent anti-wearing properties.This article has also studied the influence of MAO layer to the mechanic performance of cast aluminum substrate; and also studied thermal fatigue of MAO layer and the influence on mold-filling capacity of melting metal. In this experiment the conclusions given hereinafter are obtained:① Aluminum mold coated with MAO layer has sufficient mechanics performance to satisfy the requirement of being as amold.② The thermal fatigue performance of oxide layer obtained by MAO is much better than that of other technique such as anodic oxidation.③ Under the same condition, The flow channel coated with MAO layer is more sutible for mold—filling capacity of melting metal, the coating is thicker, the melting metal runs longer.④ The practical application of MAO on mold indicated that each mechanics performanc of the casting casted by ferroguinous mold was better than that of casting casted by aluminum mold.