Microstructures and deformation mechanisms of a G4 TiAl alloy produced by spark plasma sintering

被引：47

作者：

Jabbar, H. ^{[1
,2
]}

Monchoux, J. -P. ^{[1
,2
]}

Thomas, M. ^{[3
]}

Couret, A. ^{[1
,2
]}

机构：

[1] CNRS, CEMES, F-31055 Toulouse, France

[2] Univ Toulouse, UPS, F-31055 Toulouse, France

[3] DMSM ONERA, F-92322 Chatillon, France

来源：

ACTA MATERIALIA | 2011年 / 59卷 / 20期

关键词：

Powder consolidation; Scanning and transmission electron microscopy; Titanium aluminides; Plastic deformation; PINNING POINTS; IN-SITU; AL; DISLOCATIONS; STRESS; DEPENDENCE; CREEP; PHASE; GLIDE;

D O I：

10.1016/j.actamat.2011.09.001

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

TiAl alloys are prepared by spark plasma sintering (SPS) using a pre-alloyed powder with the so-called G4 composition (Ti(51)Al(47-)Re(1)W(1)Si(0.2)) . SPS densifications are conducted using short and classical cycles, with various dwell temperatures. The microstructure of the products is studied by scanning and transmission electron microscopy. In particular, constituent phases, grain size, precipitates and local chemical composition are determined. A double phase gamma + alpha(2) microstructure containing B2 precipitates is found in a large range of sintering temperatures. Mechanical properties at RT and creep strength at 700 degrees C/300 MPa are measured. No significant improvement of the mechanical properties is obtained with respect to those of SPS-TiAl alloys previously sintered. A study of the deformation mechanisms and the effect of the microstructure on these mechanisms is performed. Hence, the strong effect of microstructural heterogeneities from the initial powder is demonstrated. (C) 2011 Published by Elsevier Ltd. on behalf of Acta Materialia Inc.

引用

页码：7574 / 7585

页数：12

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