| Summary: | 碩士 === 國立中正大學 === 機械系 === 89 === Study was carried out to evaluate the oxidation surface and the high temperature wear characteristics of Cobalt-based and Nickel-based laser clad layers. In order to probe into the characteristics of oxidation layer, location and composition of oxide were analyzed by scanning electron microscopy (SEM) and energy dispersive X-Ray Spectrometry (EDS) and oxidation resistance was obtained by thermogravimetry analysis (TGA). Besides, the influence of the high temperature oxidation and thermal fatigue on high temperature wear test results was another focal point which was analyzed by energy dispersive X-Ray Spectrometry and observing wear trace. Finally, we compared the high temperature wear test results with wear theories to infer our wear mechanism and differentiated which wear theory it belongs to.
The result shows that the sequence of oxidation resistance was：Stellite 6, Stellite 6 with 50%Cr3C2, and Colmonoy 88. In addition, major element of their oxide was Cr. High temperature wear test results show that the wear resistance of high temperature oxidation was better than thermal fatigue and explains that all oxidation layers were advantageous for wear resistance. Moreover, major factors which affect high temperature wear test results were oxidation layer characteristics and cracks.
Surface analysis results shows that major wear mechanisms were adhesive mechanism and detach mechanism. Compared with wear theories results, high temperature wear test results belonged to Quinn’s oxidation wear theory, i.e. oxidation wear mechanism.
|
|---|
