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Journal of Materials Science

, Volume 38, Issue 10, pp 2271–2281 | Cite as

Comparison of densification and distortion behaviors of W-Ni-Cu and W-Ni-Fe heavy alloys in liquid-phase sintering

  • Yunxin Wu
  • R. M. German
  • B. Marx
  • P. Suri
  • R. Bollina
Article

Abstract

This paper aims to correlate the densification and distortion behaviors of liquid-phase sintered 80W-14Ni-6Cu and 80W-14Ni-6Fe heavy alloys with the melting characteristics of the Ni-Cu and Ni-Fe matrices. Differential thermal analysis (DTA) of die-pressed compacts reveals that the melting range of the Ni-Cu matrix is extended from 1235°C to 1453°C by the in situ alloying between elemental Cu and Ni powders, whereas the melting of the Ni-Fe matrix is limited to a narrow temperature range between 1464°C and 1480°C. Dilatometry and furnace sintering tests show that densification due to liquid-phase sintering of 80W-14Ni-6Cu starts at 1287°C and proceeds at a low rate to 1450°C, where full densification without distortion is achieved. In contrast, densification due to liquid-phase sintering of 80W-14Ni-6Fe occurs at a very high rate above 1475°C, and full density can be obtained at 1500°C. For both alloy compacts, distortion is induced by prolonging the sintering time or elevating the sintering temperature after full densification. Crack-like voids develop in the 80W-14Ni-6Cu compact to accommodate the gravity-induced distortion, while spherical pores are dominantly formed in the 80W-14Ni-6Fe compact as a result of water vapor entrapment.

Keywords

Differential Thermal Analysis Dilatometry Sinter Time Narrow Temperature Range Melting Range 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Yunxin Wu
    • 1
  • R. M. German
    • 1
  • B. Marx
    • 1
  • P. Suri
    • 1
  • R. Bollina
    • 1
  1. 1.Center for Innovative Sintered Products, P/M LabThe Pennsylvania State UniversityUniversity ParkUSA

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