退火对液氮轧制CrCoNi中熵合金组织与性能的影响

针对CrCoNi中熵合金具有优异的液氮性能,但其液氮轧制后塑性较差(<8%)所带来的难加工问题,以电弧熔炼铸态CrCoNi中熵合金为研究对象,在液氮(77 K)下对CrCoNi合金进行3道次轧制变形,总变形量为50%。随后,在650、700、800℃下保温30min进行退火。结果表明,CrCoNi中熵合金经过液氮轧制及随后退火,未发生物相结构改变。退火后,变形晶粒发生再结晶而细化,并产生∑3退火孪晶。随退火温度的升高,再结晶程度增加,延伸率提高。通过液氮轧制与中温短时间退火进行性能调控,可获得强度与韧性匹配的性能,并提高了热处理工艺效率。

退火处理对超细晶铜-锗合金力学性能的影响(英文)

超细晶Cu-0.1at%Ge合金在液氮温度下轧制后在150℃退火1 h,分别研究了超细晶铜锗合金在退火前后的显微硬度及力学性能。结果表明,通过低温退火,超细晶铜锗合金的显微硬度和强度得到提高,而均匀伸长率下降。

Texture evolution and recrystallization behaviors of Cu-Ag alloys subjected to cryogenic rolling

The texture evolution and mechanical properties of Cu-Ag alloys subjected to severe plastic deformation at cryogenic temperature（CT） were investigated and the sequent annealing behaviors were also studied.Compared with the sheets rolled at room temperature（RT） showing copper texture,the CT-rolled sheets exhibited brass texture which indicated that cross-slip was suppressed at CT,and both the ultimate tensile strength and yield strength of the sheets were increased.Due to the in-situ recrystallization mechanism,recrystallization textures in as-annealed CT-rolled sheets were randomly distributed,while the as-annealed RT-rolled sheets mainly contained cube texture.Microstructures of the rolled and annealed sheets were observed using optical microscopy and electronic back-scatter diffraction.The results show that the dynamic recovery was suppressed during CT-rolling and resulted in higher deformation energy storage.Therefore,the recrystallization of CT-rolled sheets could start at a lower temperature than that of RT-rolled sheet at the same reduction.

室温及液氮控温对轧制态Al-Sc合金力学性能及织构的影响

通过显微硬度、拉伸性能测试、显微组织分析、扫描电镜分析以及背散射电子衍射分析,研究了室温与液氮控温80%轧制变形对Al-Sc合金组织及力学性能的影响。结果表明:室温轧制与液氮控温轧制后合金的硬度分别为105 HV0. 3和162 HV0. 3,抗拉强度、屈服强度、伸长率分别为335 MPa、296 MPa、5. 5%和443 MPa、415 MPa、6. 7%;轧制后合金中多为小角度晶界,室温与液氮控温轧制后平均晶粒尺寸分别为40μm和1μm;由于层错能的影响,合金液氮控温轧制之后的主要织构类型为Brass织构{110}<112>、S织构{123}<634>和Copper织构{112}<111>。