Characterization and <Emphasis Type="Italic">in-situ</Emphasis> formation mechanism of tungsten carbide reinforced Fe-based alloy coating by plasma cladding

The precursor carbonization method was first applied to prepare W-C compound powder to perform the in-situ synthesis of the WC phase in a Fe-based alloy coating.The in-situ formation mechanism during the cladding process is discussed in detail.The results reveal that fine and obtuse WC particles were successfully generated and distributed in Fe-based alloy coating via Fe/W-C compound powders. The WC particles were either surrounded by or were semi-enclosed in blocky M7C3carbides. Moreover, net-like structures were confirmed as mixtures of M23C6and α-Fe; these structures were transformed from M7C3. The coarse herringbone M6C carbides did not only derive from the decomposition of M7C3but also partly originated from the chemical reaction at the α-Fe/M23C6interface. During the cladding process, the phase evolution of the precipitated carbides was WC → M7C3→ M23C6+ M6C.