Experimental Research On Laser Remelted Nanocrystalline Nickel Coating Oriented By Jet Electroforming

Nano-materials get more and more attention because its have many special quality compared as traditional materials.In this paper, the nanocrystalline nickel coating whose electrical source inevitably are direct and pulse current was made by jet electroforming, then remelted the coating in order to eliminate the limitations. Choose propriety remelting process parameters, which diminished the surface crystal, increased the coating's compact quality, improved the combination between coatings and the base metal,and implemented the transformation form mechanism combination to metallurgy combination. The major conclusions got in this dissertation are presented as follows:1. Deposited the nanocrystalline nickel coating on the base metal by jet electroforming system, direct and pulse supply, and watts deposition liquid, then laser remelted the coating, got the laser remelted nanocrystalline nickel coating by jet electroforming.2. Analyzed the coating's microstructure by modern analysis methods,. And the analysis showed: electric current density have huge influence to the nanocrystalline nickel coating at direct current, the change trend about the size of crystal is increased d firstly decreased then; on the pulse condition, the coating's size of crystal are obviously diminished, and the nanocrystalline coating can be get on the higher electric current density; after laser remelted, the coating's size of crystal are obviously diminished on the remelted district.3. Analyzed the coating's mechanism performance by testing equipment. Founded out: the coating's microhardness profiles obviously increased but the strain-stress characterization and the corrosion resistance have a little of decrease compared as the coating only jet electroforming. The main cause are that there are many cracks in the remelted coating and the soft district plentyly exist in the base metal which made the mechanism performance decreased and corrosive liquid filtering increased.4. Compared with the analyzing result and the mathematics model's calculation result. The calculation result was basic consistent of the analyzing result and got a series of laser process optimize parameter.