Crystal Structure and Carbon Vacancy Hardening of (W0.5Al0.5)C1−x Prepared by a Solid‐State Reaction

ChemPhysChem - Tập 6 Số 10 - Trang 2099-2103 - 2005
Jun‐Min Yan1,2, Xianfeng Ma2, Wei Zhao2, Huaguo Tang1,2, Changjun Zhu1,2, Shuguang Cai1,2
1Graduate School of the Chinese Academy of Sciences, Changchun 130022, China
2Laboratory of Materials and Devices, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China,

Tóm tắt

AbstractNovel solid solutions of aluminum in tungsten carbide (WC) with or without carbon vacancies, which can be expressed by the chemical formula (W0.5Al0.5)C1−x (x=0.0–0.5), have been synthesized by the solid‐state reaction of W0.5Al0.5 alloy and the proper amount of carbon at around 1673 K in vacuum. The reaction time decreases from 73 to 50 h on increasing the carbon vacancy concentration from 0 to 50 %. The formation of the intended products is certified, by X‐ray diffraction, environmental scanning electron microscopy–energy‐dispersive X‐ray analysis, and inductively coupled plasma–atomic emission spectroscopy, even though the carbon vacancy concentration reaches the astonishing value of 50 %. The as‐prepared (W0.5Al0.5)C1−x samples have been identified as the hexagonal WC‐type structure belonging to the space group P6m2 (Z=1). Moreover, the crystallographic results reveal that the substituting aluminum atoms in the WC are located in the 1a site (the W atom position of the WC structure) and the cell parameters decrease slightly with increasing vacancy concentration. The hardness of the (W0.5Al0.5)C1−x system increases up to a maximum 2659 kg mm−2 at a carbon vacancy concentration of about 35 %, and the density of (W0.5Al0.5)C1−x is far lower than that of WC.

Từ khóa


Tài liệu tham khảo

in V. K. Sarin, 1981, Advances in Powder Technology: Papers Presented at the 1981 ASM Materials Science Seminar, 253

10.1016/0272-8842(92)90082-O

10.1016/S0263-4368(98)00044-4

Lindhal P., 1993, J. Hard Mater., 4, 187

10.1016/S0263-4368(00)00002-0

10.1016/S0263-4368(96)00023-6

10.1016/S0263-4368(01)00026-9

10.1016/S1044-5803(02)00181-X

10.1002/zaac.19261560105

1990, Binary Alloy Phase Diagrams

Toth L. E., 1971, Transition Metal Carbides and Nitrides

10.1116/1.573700

10.1016/0966-9795(93)90028-T

10.1016/S0925-8388(02)00760-0

10.1021/j150228a003

10.1103/PhysRevLett.86.3348

1989, ASM Engineered Materials Reference Book, 182

Scussel in H. J., 1992, ASM Handbook,, 795

10.1016/S0925-8388(96)02732-6

Thông tin
Thông tin xuất bản

ChemPhysChem

Tập 6 Số 10

2099-2103

Thông tin tác giả