限制模压变形均匀性研究与定量表征

采用限制模压法(Constrained Groove Pressing,CGP)变形商业5052铝合金,考察了经不同道次变形后试样的显微硬度均匀性,即CGP的变形均匀性,并讨论了模具齿宽对变形均匀性的影响。结果表明,CGP变形能够显著提高5052铝合金的显微硬度值,但模具齿宽对显微硬度的提高影响不大;CGP变形1道次后,试样显微硬度分布极不均匀,但是随变形道次的增加,试样显微硬度分布趋于均匀;弯曲延展区的存在是导致CGP变形不均匀的根本原因,这种不均匀性可通过增加变形道次或增加模具齿宽加以改善。

Investigation and quantitative characterization of homogeneity in constrained groove pressing

Samples of 5052 Al were subjected to constrained groove pressing (CGP) under the conditions with different tooth widths and pass numbers.The microhardness was recorded on the polished XOZ plane of each sample and the results were plotted to provide a pictorial depiction of the homogeneity.The results show that the microhardness increases significantly after CGP but is independent upon tooth width.The microhardness distribution is homogeneous in the non-pressed condition but inhomogeneous after a single pass and then reasonably homogeneous in subsequent passes.The results reveal that the essential reason of inhomogeneity is the existence of the interface region between the shear and flat regions.It is shown that good homogeneity may be achieved through CGP pressing by increase the number of pass or the width of pressing tooth.