The evolution of microstructure and texture at four strain levels was investigated in Ni-5 at%W alloy by means of electron backscatter diffraction(EBSD)technique.The deformation microstructure evolves gradually from microbands(MBs)to typical lamellar structures with strain increasing in cold-rolled materials,while only lamellar structures in heavily cold-rolled materials.Subsequently,quantitative analysis of microstructure and texture was performed.It indicates that the texture is a typical pure metal deformation texture,but a few cube and rolling direction(RD)-rotated cube orientations also can be observed in the deformed samples.The use of high-temperature annealing enables an area fraction of cube orientation>95%to be obtained for high strained substrate.In addition,it is worth noting that the point-to-point misorientation inside the band with various orientations is found to keep quite low.But the point-to-origin misorientation over the same distance is dependent on strain and orientation type in the band.The cube-oriented regions were characterized by a high accumulated orientation gradient,close to 28°,compared to the non-cube-oriented regions.This means that the accumulated orientation gradient only occurs in the cube band with the reduction of 98%,which partly explains the formation of strong cube texture after high-temperature annealing.
应用电子背散射衍射(EBSD)和取向成像显微技术(OIM)研究了形变量对Ni-5 at%W合金退火过程中晶界特征分布(GBCD)的影响。合金经77%、89%和98%冷轧后分别在不同温度下进行退火。试验结果表明:较小的形变量(77%、89%)相比于较高的形变量(98%),前者更容易在随后的再结晶退火过程中激发出更多的低ΣCSL(coincidence site lattice,Σ≤29)特殊晶界。在同一形变量下,随着温度的升高,Σ3的比例随之下降;在相同的退火温度下,随着形变量的增大,Σ3的比例也随之下降。与此同时,小角度晶界含量不断增加,立方织构逐渐尖锐。
