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 pr...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 M7C3 carbides. Moreover, net-like structures were confirmed as mixtures of M23C6 and α-Fe; these structures were transformed from M7C3. The coarse herringbone M6C carbides did not only derive from the decomposition of M7C3 but also partly originated from the chemical reaction at the α-Fe/M23C6 interface. During the cladding process, the phase evolution of the precipitated carbides was WC → M7C3 → M23C6 ＋ M6C.展开更多
Zirconium tungsten oxyfluoride,ZrWO4F2,was firstly synthesized with the pr ecursor route.The composition of the compound was determined by combi ning the results of ICP and XPS.The in dexed powder X-ray diffraction pa...Zirconium tungsten oxyfluoride,ZrWO4F2,was firstly synthesized with the pr ecursor route.The composition of the compound was determined by combi ning the results of ICP and XPS.The in dexed powder X-ray diffraction pattern of this compound indicates t hat it is a pure phase,orthorhombic c rystal system,space group D 22 =P2 1 22and a=15.32（2）*!,b=13.877（7）*!,c=8.42（2）*!.Combining the results of the DTA-T GA curves from room temperature to 700℃and XRD patterns in different temperatures the mechanism was revealed during the solid precursor（1）been heated to 700℃.The zirconium tu ngsten oxyfluoride was considered t o be a metastable com-pound.The ascertaining of annealin g time and temperature is the key of handling.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51379070)
文摘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 M7C3 carbides. Moreover, net-like structures were confirmed as mixtures of M23C6 and α-Fe; these structures were transformed from M7C3. The coarse herringbone M6C carbides did not only derive from the decomposition of M7C3 but also partly originated from the chemical reaction at the α-Fe/M23C6 interface. During the cladding process, the phase evolution of the precipitated carbides was WC → M7C3 → M23C6 ＋ M6C.
文摘Zirconium tungsten oxyfluoride,ZrWO4F2,was firstly synthesized with the pr ecursor route.The composition of the compound was determined by combi ning the results of ICP and XPS.The in dexed powder X-ray diffraction pattern of this compound indicates t hat it is a pure phase,orthorhombic c rystal system,space group D 22 =P2 1 22and a=15.32（2）*!,b=13.877（7）*!,c=8.42（2）*!.Combining the results of the DTA-T GA curves from room temperature to 700℃and XRD patterns in different temperatures the mechanism was revealed during the solid precursor（1）been heated to 700℃.The zirconium tu ngsten oxyfluoride was considered t o be a metastable com-pound.The ascertaining of annealin g time and temperature is the key of handling.
