Cobalt-doped Ti-48Al-2Cr-2Nb alloy fabricated by cold compaction and pressureless sintering

Xia, Y.1; Yu, R.2; Schaffer, G. B.1; Qian, M.1

2013-07

10.1016/j.msea.2013.03.023

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING   影响因子和分区

0921-5093

An addition of 1.5 at% Co to Ti-48Al-2Cr-2Nb (in at%) transformed the alloy from essentially unsinterable to fully sinterable at 1300 degrees C. This, together with a simple powder coating process developed recently, has allowed near-net shape fabrication of the alloy for the first time by cold compaction and pressureless sintering. The addition of Co results in the formation of an intermediate face centred cubic (fcc) CoAl2Ti phase prior to 1220 degrees C during heating. It subsequently reacts with an alpha phase leading to the formation of a Co-containing, wettable sintering liquid through a two-step process, CoAl2Ti+alpha -> Liquid at 1256.2 degrees C and CoAl2Ti+alpha ->gamma-TiAl+Liquid at 1267.2 degrees C, and therefore full densification of the alloy. Without Co, sintering of the Ti-48Al-2Cr-2Nb alloy powder at 1300 degrees C is controlled by the slow self-diffusion of Ti and interdiffusion of Ti and Al according to the activation energy determined. Transmission electron microscopy (TEM) identified an fcc CoAl2Ti phase and a hexagonal close packed (hcp) Co-enriched Ti(Al, Co, Cr, Nb) phase in the final as-sintered Ti-48Al-2Cr-2Nb-1.5Co alloy. They both form during cooling at 1240 degrees C through Liquid+alpha -> CoAl2Ti+Ti (Al, Co, Cr, Nb). The tensile and compressive properties of the as-sintered Ti-48Al-2Cr-2Nb-1.5Co alloy were compared to the original General Electric (GE) Ti-48Al-2Cr-2Nb alloy fabricated by casting or metal injection moulding. (C) 2013 Elsevier B.V. All rights reserved.

Titanium aluminide Sintering Cobalt Mechanical properties

SCI ; EI

英语

其他

China Scholarship Council[] ; Australian Research Council[] ; University of Queensland[]

Science & Technology - Other Topics ; Materials Science ; Metallurgy & Metallurgical Engineering

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:000319088100023

ELSEVIER SCIENCE SA

20131816306598

Activation energy ; Aluminum alloys ; Chromium alloys ; Cobalt ; Cobalt alloys ; Compaction ; Fabrication ; High resolution transmission electron microscopy ; Injection molding ; Liquids ; Mechanical properties ; Powder coatings ; Powder metals ; Sintering ; Ternary alloys ; Titanium alloys ; Titanium castings

Aluminum Alloys:541.2 ; Titanium and Alloys:542.3 ; Chromium and Alloys:543.1 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Optical Devices and Systems:741.3 ; Coating Materials:813.2 ; Materials Science:951

MATERIALS SCIENCE

Web of Science

1.Univ Queensland, Sch Mech & Min Engn, ARC Ctr Excellence Design Light Met, Brisbane, Qld 4072, Australia
2.South Univ Sci & Technol China, Dept Micronano Mat & Device, Shenzhen 518055, Peoples R China

Xia, Y.,Yu, R.,Schaffer, G. B.,et al. Cobalt-doped Ti-48Al-2Cr-2Nb alloy fabricated by cold compaction and pressureless sintering[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2013,574:176-185.

Xia, Y.,Yu, R.,Schaffer, G. B.,&Qian, M..(2013).Cobalt-doped Ti-48Al-2Cr-2Nb alloy fabricated by cold compaction and pressureless sintering.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,574,176-185.

Xia, Y.,et al."Cobalt-doped Ti-48Al-2Cr-2Nb alloy fabricated by cold compaction and pressureless sintering".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 574(2013):176-185.