Wear Characteristics of Cobalt-Base Superalloy Melted by Plasma Transferred Arc

• Main Authors: Lin, Hung-Mao, 林宏茂
• Other Authors: Chen Li-Hui, Lui Truan-Sheng
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/58682864186818194987

碩士 === 國立成功大學 === 材料科學(工程)學系 === 86 === The surface overlaying treatment is aimed to give different special properties to surfaces and substrates of materials. Microhardness, wear-resistance, corrosion-resistance etc. can be enhanced after treatment. Due to superior mechanical properties, spheroidal graphite (SG) cast irons are widely used in industries such as machine production, automobile components etc. These components generally need to have surfaces with higher microhardness to increase wear-resistance while their cores need to main The results reveal that the overlayer specimen after overlaid can be divided into overlayer, interface region and substrate. The interface region includes interfacial layer and partially melted region which is mainly composed of fine pearlite and ledeburite. The substrate includes heat effect region. The Stellite 6 overlayer melted on SG iron cast with 3.5wt% carbon under low overlaying current (I=140A) is a dentritic structure with M7C3 and M23C6 carbides. On the other hand, the Stellite 1 overlaye The microhardness of Stellite alloy overlayers increases with overlaying currents and so does the amount of carbides. The main reason is that the overlayers are diluted by substrates. Hence, it shows that the microhardness of overlayers is related to overlaying current and the amount of carbides. The results of cutting wear test reaveal that the flank wear width of Stellite alloy overlayers tend to increase as the sliding distance and cutting speed . The flank wear width of Stellite 6 overlayer redu In the cutting wear test, the wear mechanisms of overlayers are mainly plastic groove, surface polish and adhesive wear as adhered to overlayers. Others minor mechanisms include brittle crack and fracture. Among these, the case to plastic groove include microcutting and plough.