Design,Fabrication And Properties Study Of New Ti-Zr-Al-V-B Alloy

Titanium and titanium alloys have been widely used in chemical engineering,biomedicine,especially aerospace aspects and other fields,which is mainly due to their excellent physical and chemical properties: low density,high specific strength,good corrosion resistance et al.Zirconium and titanium belong to the same group(?B)in the periodic table of elements,and Zr have similar physic-chemical properties with Ti,but Zr and Zr alloys also have small neutron absorption area,low thermal expansion coefficient,oxidation resistance and anti-radiation et al.And Zr and Zr alloys play a important role in nuclear industry and acetic acid industry.However,with the rapid development of the aerospace industry and the harsh space service environment,more higher requirements are put forward for the space structure materials.Some studies have added Zr to TC4 alloy,and the prepared ZrTiAlV alloy have obtained higher strength and better plasticity.Based on the research of ZrTiAlV quaternary alloy,the Al-5Ti-1B intermediate alloy was added into ZrTiAlV alloy to get a refined and strengthened boron-contained alloy.The microstructure and mechanical properties of the alloys,under different components and different heat-treatment situations,are studied by various experimental methods.A series of ZrTiAlVB alloys are prepared by vacuum non-consumable electro-arc furnace,and the effect of boron on the phases,microstructure and mechanical properties of the alloy is also studied.The results show that a new phase TiB is formed and mainly distributed along the grain boundary and the as-cast grain size of the alloy is obviously recuced and the ? lath is refined.After rolling at 870? and air-cooling,the mechanical properties of the alloys with 0.26 at.% boron are much higher than that of the alloys without boron,the yield strength,tensile strength and elongation of 0.26 B were increased by 11.10%,19.98% and31.55%,respectively.But the alloy matrix structure is coarsened and mechanical properties decreased after annealing at 700 ?.In addition,the microstructures and properties of alloys with different compositions are investigated at 870? and 950?.The martensite phases ?" and ?? are obtained after water quenching;the yield strength of 0.11 B alloy is only 603 MPa when the alloy is rolled at 950?,and the alloy has better properties after rolling and water quenching at 870? and 0.16 B alloy obtains a good mechanical properties,its yield strength,tensile strength and elongation reach 1092 MPa,1467MPa and 8.68%,respectively.