Effect Of Hydrogenization On Microstructure And Properties And Thermo-deformation Behavior Of TC4Titanium Alloy

In this work, the effects of hydrogen treatment on the microstructure andproperties and thermo-deformation behavior of TC4alloy were invest by means ofmicrostructure observation, hardness and tensile performance testing, thermalcompression tests and other means of hydrogen treatment on TC4alloymicrostructure, mechanical properties and thermal deformation behavior.Hydrogen as a temporary alloying element, the use of hydrogen-inducedthermoplastic, reduce heat deformation resistance, improved alloy thermalprocessing performance, so that after forming titanium alloy has good mechanicalproperties.The results showed that the hydrogenation process parameters affect thehydrogen content of TC4alloy. Hydrogen TC4alloy infiltrated tissue afterrefinement. Hydrogen content increased, resulting in generation of martensite, andthe number increases, α slats forming a large number of internal twinning, strip βphase number of dislocations formed inside; hydrogen content reaches a certainamount, the alloy hydride formation.Hydrogenation treatment makes the room temperature increases. Prolongedhydrogenation time, the hydrogen content increases, the Brinell hardness valueincreases; room temperature, the hydrogen-containing sample elongation is low.600℃,700℃stretching, elongation increases, but as the hydrogen contentincreases, higher strength, ductility decreases. Hydrogen content of the samesample, as the stretching temperature, the strength is reduced, increased ductility.Compression temperature, strain rate is reduced, resulting in decreasedcompressive strength; under the same deformation conditions, the compressionstrength and the hydrogen content in a U-shaped relationship; the appropriatehydrogen content, the compressive strength reaches a minimum value.Deformation temperature, TC4alloy flow stress decreases; appropriatehydrogen content of the flow stress reduction; Set hydrogen flow stress increaseswith strain rapid decline, the steady-state flow stress peak only50-70%,significantly lower than that of hydrogenated alloys.Hot compression deformation results in distortion of TC4alloy, partialprecipitation plexiform parallel secondary α phase; TC4alloy with high hydrogencontent of the grain boundary phase portion broken β, α lath size decreases, the formation of small equiaxed α equal. Temperature deformation, the deformationrate decreases, the β phase distortion decreases, α lath small size, the grainboundary is obvious; deformation temperature decreases, the strain rate increases,the deformed strip with β, α twisted strip, grain boundaries become blurred.This article identifies750℃annealing8hours dehydrogenation process is abetter technology; dehydrogenation of hydrogenated TC4alloy microstructuremorphology after hydrogen permeation craft, hydrogenation temperature is high,dehydroepiandrosterone tissue remains after hydrogen permeation aftermorphology, hydride decomposed hydrogen escape, β-phase grain boundariesbecome clear, relatively small organization; TC4alloy of hydrogenated after hotdeformation, and then to a vacuum dehydrogenation treatment, the hardness ishigher than the original alloys and thermal deformation of hydrogenated alloys.