论文部分内容阅读
采用钟罩浸块铸造法制备了不同碳纳米管含量的镁锌合金铸锭,经热挤压后制备出不同碳纳米管含量变形镁锌合金,研究碳纳米管作为增强材料加入到不含铝的镁锌二元合金中,对其组织和性能产生的影响。利用光学显微镜、扫描电镜及拉伸强度实验机对其显微组织形态及力学性能进行了分析。结果表明,碳纳米管的加入能够显著细化合金铸锭的晶粒起到了细化树枝晶二次枝晶臂间距和转变晶体生长方式的作用,且经过热挤压变形后组织变得更加均匀细小,具有细晶组织;碳纳米管对热挤压镁锌合金的力学性能有增强作用,提高了镁锌合金的抗拉强度、屈服强度、延伸率,当加入量为1.0%时,分别达到最大值219.740,215.969 MPa,27%,其中以延伸率的提高最为显著,抗拉强度和屈服强度值趋于稳定,可得碳纳米管加入到镁锌合金中,起到了较好的复合效果,对晶粒和晶界起到细化和强化的作用,使得该材料具有较高塑形的同时没有降低其强度;合金的断裂特征为典型韧性断裂,有较深的圆形韧窝和撕裂棱组成,碳纳米管与基体合金结合紧密,在拉伸断口处的白色须状物质即为表面被基体合金包覆的碳纳米管。
Magnesium-zinc alloy ingots with different content of carbon nanotubes were prepared by bell-block dipping method. Magnesium-zinc alloy with different content of carbon nanotubes was prepared by hot extrusion. The effect of carbon nanotubes as reinforcements on aluminum- Of the magnesium-zinc binary alloy, its organization and performance of the impact. The microstructure and mechanical properties were analyzed by optical microscope, scanning electron microscope and tensile strength tester. The results show that the addition of carbon nanotubes can remarkably refine the grains of the alloy ingot, which plays a role in refining the dendrite secondary dendrite arm spacing and crystal growth mode transformation, and the structure becomes more uniform after hot extrusion deformation Fine, with fine grain structure; carbon nanotubes on the mechanical properties of hot-extruded magnesium-zinc alloy has an enhanced role in improving the tensile strength of magnesium-zinc alloy, yield strength, elongation, when the addition of 1.0% Maximum 219.740,215.969 MPa, 27%, of which the most significant increase in elongation, tensile strength and yield strength values tend to be stable, can be added to the carbon nanotubes magnesium alloy, played a good compound effect, The grains and grain boundaries play the role of refinement and strengthening, making the material has a higher shape without reducing its strength; alloy fracture characteristics of a typical ductile fracture, with a deep round dimples and tear Rib composition, carbon nanotubes and matrix alloy bonded tightly in the tensile fracture of the white whisker material is the surface of the substrate alloy coated carbon nanotubes.