Fabrication of Sintered Compact of Fe-TiB2 Composites by Pressureless Sintering of (FeB+TiH2) Powder Mixture
0
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
A sintered body of TiB2-reinforced iron matrix composite (Fe-TiB2) is fabricated by pressureless-sintering of a mixture of titanium hydride (TiH2) and iron boride (FeB) powders. The powder mixture is prepared in a planetary ball-mill at 700 rpm for 3 h and then pressurelessly sintered at 1300, 1350 and 1400oC for 0-2 h. The optimal sintering temperature for high densities (above 95% relative density) is between 1350 and 1400oC, where the holding time can be varied from 0.25 to 2 h. A maximum relative density of 96.0% is obtained from the (FeB+TiH2) powder compacts sintered at 1400oC for 2 h. Sintered compacts have two main phases of Fe and TiB2 along with traces of TiB, which seems to be formed through the reaction of TiB2 formed at lower temperatures during the heating stage with the excess Ti that is intentionally added to complete the reaction for TiB2 formation. Nearly fully densified sintered compacts show a homogeneous microstructure composed of fine TiB2 particulates with submicron sizes and an Fe-matrix. A maximum hardness of 71.2 HRC is obtained from the specimen sintered at 1400oC for 0.5 h, which is nearly equivalent to the HRC of conventional WC-Co hardmetals containing 20 wt% Co.
Abstract
A sintered body of TiB2-reinforced iron matrix composite (Fe-TiB2) is fabricated by pressureless-sintering of a mixture of titanium hydride (TiH2) and iron boride (FeB) powders. The powder mixture is prepared in a planetary ball-mill at 700 rpm for 3 h and then pressurelessly sintered at 1300, 1350 and 1400oC for 0-2 h. The optimal sintering temperature for high densities (above 95% relative density) is between 1350 and 1400oC, where the holding time can be varied from 0.25 to 2 h. A maximum relative density of 96.0% is obtained from the (FeB+TiH2) powder compacts sintered at 1400oC for 2 h. Sintered compacts have two main phases of Fe and TiB2 along with traces of TiB, which seems to be formed through the reaction of TiB2 formed at lower temperatures during the heating stage with the excess Ti that is intentionally added to complete the reaction for TiB2 formation. Nearly fully densified sintered compacts show a homogeneous microstructure composed of fine TiB2 particulates with submicron sizes and an Fe-matrix. A maximum hardness of 71.2 HRC is obtained from the specimen sintered at 1400oC for 0.5 h, which is nearly equivalent to the HRC of conventional WC-Co hardmetals containing 20 wt% Co.
참고문헌 (14)
- B. Du, , Appl. Surf. Sci., 254, pp.6489~ (2008)
- B. Du, , Mater. Lett., 62, pp.689~ (2008)
- M. Darabara, , Surf. Coat. Technol., 201, pp.3518~ (2006)
- W. Xibao, , Surf. Coat. Technol., 192, pp.257~ (2005)
- A. Anal, , J. Mater. Process. Technol., 172, pp.70~ (2006)
- B. Li, , J. Mater. Sci., 44, pp.3909~ (2009)
- O. K. Lepakova, , Combust. Explos. Shock Waves, 36, pp.575~ (2000)
- C.C. Degnan, , Metall. Mater. Trans. A, 33, pp.2973~ (2002)
- L. Gai, , Inter.J. Refract. Met. Hard Mater., 45, pp.141~ (2014)
- O. K. Lepakova, , J. Mater. Sci., 39, pp.3723~ (2004)
- R.M. Aikin, , JOM, 49, pp.35~ (1997)
- Xuan-Khoa Huynh, "FeB와 TiH2 혼합분말의 유성볼밀 및 후속열처리에 의한 Fe-TiB2 나노복합분말 in situ 제조", 대한금속·재료학회지, 55(1), pp.10~15 (2017), 대한금속·재료학회[DOI]
- R.M. German, "Powder Metallurgy of Iron and Steel", pp.192~ (1998), John Wiley & Sons Inc.
- K.J.A. Brooks, "World Directory and Handbook of Hardmetals and Hard Materials", pp.96~ (1996), International Carbide Data