Study Of Biomimetic Gradient Nano-composite Coatings On Metal Materials Surface

The gray iron and the powder metallurgy parts are two kinds the widely used materials in the industry. Due to limitation of processing technology, the surface property of materials is poor. Therefore, it is essential to improve surface properties by surface modification technology.The hierarchical gradient character of nature materials such as skeleton ,bamboo and wood are designed on the gray iron surface and the powder metallurgy parts surface in the paper.The two kinds of methods are used both laser cladding and composite electrodeposition.The biomimetic gradient nano-composite coating are prepared.The experiment optimization design method are used to the craft parameters optimal.The results are concluded the craft parameters are best when power of laser cladding is 3.0kw and the scanning speed is 90mm/min on gray iron surface. Similar to the craft parameters are best when power of laser cladding is 2.5kw and the scanning speed is 90mm/min on powder metallurgy materials surface.The results are concluded in composite electrodeposition that the crafe parameters are best when current density is 40mAcm-2,pH value is 3～4,stiring style is supersonic vibration mix mechanical stiring, content of nano-particulates is 20g/l.The influence of craft parameters are discussed on gray iron and powder metallurgy surface modification coating during laser cladding.The microstrcture are effected by content, the craft parameters, shape control factor G/υ(Gradient of temperature/coagulation speed) but the shape control factor is decided by craft parameters.The microstructure of coating on gray iron surface and powder metallurgy...