Microstructural Development and Mechanical Properties of PM Ti-45Al-2Nb-2Mn-0.8 vol.%TiB_2 Processed by Field Assisted Hot Pressing

作     者：R.Munoz-Moreno E.M.Ruiz-Navas B.Srinivasarao J.M.Torralba 

作者机构：Department of Materials Science and EngineeringUniversidad Carlos Ⅲ de MadridAvda.Universidad 3028911 LeganésMadridSpain IMDEA Materials InstituteC/Eric Kandel 228906 GetafeMadridSpain 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2014年第30卷第11期

页      面：1145-1154页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Funding from the Spanish Ministry of Science and Innovation through projects MAT2009-14547-C02-01 and MAT200914547-C02-02 The Madrid Regional Government partially supported this project through the ESTRUMAT (Grant No.P2009/MAT-1585) 

主　　题：Titanium aluminides Powder metallurgy Microstructure Mechanical properties Field assisted sintering 

摘      要：A γ-TiAI intermetallic alloy, Ti-45Al-2Nb-2Mn （at.%）-0.8 vol.%TiB2, has been processed from gas atomized praalloyed powder by field assisted hot pressing （FAHP）. An initial analysis of the prealloyed powder helped on the understanding of the intermetallic sintering behavior. Atomized powder consisted of α metastable phase that transformed into α2＋γ equilibrium phases by thermal treating. Different powder particle microstructures were found, which influence the microstructure development of the FAHP T-TiAI material depending on the sintering temperature. Duplex, nearly lamellar and fully lamellar microstructures were obtained at the sintaring temperatures above 1000 ℃. Lower consolidation temperatures, below 1000 ℃, led to the formation of an AI rich phase at powder particle boundaries, which is deleterious to the mechanical properties. High compressive yield strength of 1050 MPa was observed in samples with FAHP duplex microstructures at room temperature. Whereas nearly lamellar and fully lamellar microstructures showed yield strength values of 655 and 626 MPa at room temperature and 440 and 425 MPa at 750 ℃, respectively, which are superior in comparison to similar alloys processed by other techniques. These excellent properties can be explained due to the different volume fractions of the α2 and γ phases and the refinement of the PM microstructures.