论文标题
加工参数对HPT镍碳纳米管复合材料的机械性能的影响
Influence of Processing Parameters on the Mechanical Properties of HPT-Deformed Nickel Carbon Nanotube Composites
论文作者
论文摘要
镍纳米管复合材料具有不同量的碳纳米管在不同变形温度下高应变到高应变的高压扭转变形，在这些变形温度下，没有观察到镍基质微结构的进一步细化。平均镍晶尺寸随着HPT变形温度的升高而增加，而碳纳米管亲聚体的大小显着降低。另外，金属基质中的聚集物的分布变得更加均匀。为了研究HPT变形复合材料的机械性能，进行了单轴拉伸和压缩测试。根据HPT变形温度和所得的微结构，发生脆性或延性骨折。 HPT变形温度升高会导致机械性能的各向异性降低，这主要是由于碳纳米管亲聚体的收缩而引起的。结果表明，调整HPT变形温度是优化微结构和机械性能的关键。
Nickel carbon nanotube composites with varying amounts of carbon nanotubes are deformed by high pressure torsion at different deformation temperatures to high strains, where no further refinement of the Nickel matrix microstructure is observed. Mean Nickel grain sizes increase with increasing HPT deformation temperature, while the size of the carbon nanotube agglomerates is significantly reduced. Additionally, the distribution of the agglomerates in the metal matrix becomes more homogenous. To investigate the mechanical performance of the HPT deformed composites, uniaxial tensile and compression tests are conducted. Depending on the HPT deformation temperature and the resulting microstructure, either brittle or ductile fracture occurs. Increased HPT deformation temperatures induce a decrease in the anisotropy of the mechanical properties, mainly caused by a shrinking of the carbon nanotube agglomerates. It is shown, that tuning the HPT deformation temperature is the key for optimizing both the microstructure and the mechanical performance.
