纳米晶Al的制备及拉伸性能(Ⅰ)

SYNTHESIS AND TENSILE PROPERTIES OF NANOCRYSTALLINE Al (Ⅰ)

采用活性氢等离子蒸发法制备出纳米Al粉体，然后将粉体冷压成块体经适当热处理的纳米Al块体试样的屈服强度σ0．2是普通粗晶Al的12～16倍，断裂强度σb是粗晶Al的5～6倍，断裂延伸率达4％，为典型的韧窝塑性断口．

Nano-Al particfes prepared by plasma evaporation method were compacted at room temperature into disc-shape samples with a dimension of 25×2mm. After annealing at 620℃ for 40min, the samples were cold-rolled to form sheets with thickness of lmm and length of 40mm. The sheets were machined into dogbone-like samples for tensile test. Densities of the sampfes are all 99%of theoretical density. Average grain size determined by XRD and TEM observation is about 53nm.The results of uniaxial tensile test showeds yield strength 0.2 and breaking strength of nano-Al densified by cold deformation are 12-16 and 5-6 times that of annealed coarse-grained Al, respectively.Its elongation b is about 28% greater than that of cold-rolfed coarse-grained Al and 2 times that of undeformed nano-Al.The efFects of cold deformation on the properties of nano-Al were discussed.