Using TiAl alloy to substitute superalloy is a hot topic in aeroengine industry because of its low density, high elevated temperature strength, and anti-oxidization ability. In this research, Ti-47.5AL-2Cr-2Nb-0.2B al...Using TiAl alloy to substitute superalloy is a hot topic in aeroengine industry because of its low density, high elevated temperature strength, and anti-oxidization ability. In this research, Ti-47.5AL-2Cr-2Nb-0.2B alloy was used as the test material. By applying a combination process of ceramic shell mold and core making, vacuum arc melting and centrifugal pouring, and heat isostatic pressing （HIP） and heat treatment （HT） etc., the TiAl vortex agitator casting for aeroengine was successfully made. This paper introduced key techniques in making the TiAl vortex agitator with investment casting process, provided some experimental results including mechanical properties and machinability, and explained some concerns that could affect applications of TiAl castings.展开更多
Spark plasma sintering（SPS） was used to weld the ceramics,eg,Cr3C2 and metal,Ni in this paper.It is found that the SPS can weld the Cr3C2 and Ni plates at lower temperatures and shorter holding time comparing with t...Spark plasma sintering（SPS） was used to weld the ceramics,eg,Cr3C2 and metal,Ni in this paper.It is found that the SPS can weld the Cr3C2 and Ni plates at lower temperatures and shorter holding time comparing with that of hot-pressing（HP）.The binding strength was 113 MPa when the temperature was 1000 ℃ by SPS,compared with 10 MPa by HP at the same temperature.SPS remarkably enhances the atom diffusion in welding.Thermodynamics analysis at different welding temperatures and holding times of SPS or HP shows that the local temperature gradient,different from the past effects of by-passing current,is the dominative mechanism of the SPS welding.展开更多
文摘Using TiAl alloy to substitute superalloy is a hot topic in aeroengine industry because of its low density, high elevated temperature strength, and anti-oxidization ability. In this research, Ti-47.5AL-2Cr-2Nb-0.2B alloy was used as the test material. By applying a combination process of ceramic shell mold and core making, vacuum arc melting and centrifugal pouring, and heat isostatic pressing （HIP） and heat treatment （HT） etc., the TiAl vortex agitator casting for aeroengine was successfully made. This paper introduced key techniques in making the TiAl vortex agitator with investment casting process, provided some experimental results including mechanical properties and machinability, and explained some concerns that could affect applications of TiAl castings.
基金Funded by the National Natural Science Foundation of China(No.U12301013)the Innovation Fund of Wuhan University of Technology(No.123243005)
文摘Spark plasma sintering（SPS） was used to weld the ceramics,eg,Cr3C2 and metal,Ni in this paper.It is found that the SPS can weld the Cr3C2 and Ni plates at lower temperatures and shorter holding time comparing with that of hot-pressing（HP）.The binding strength was 113 MPa when the temperature was 1000 ℃ by SPS,compared with 10 MPa by HP at the same temperature.SPS remarkably enhances the atom diffusion in welding.Thermodynamics analysis at different welding temperatures and holding times of SPS or HP shows that the local temperature gradient,different from the past effects of by-passing current,is the dominative mechanism of the SPS welding.
