The effects of carbon nanotubes on the mechanical and wear properties of AZ31 alloy

• 1、School of Materials Science and Engineering, Southwest Jiaotong University,Chengdu,610031
• 2、School of Materials Science and Engineering, Southwest Jiaotong University,Chengdu&#

Abstract：Carbon nanotubes (CNTs) reinforced AZ31 matrix nanocomposites were successfully fabricated using powder metallurgy method followed by hot extrusion. And the influence of CNTs on microstructure, mechanical properties and wear properties were investigated systematically by the optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), hardness test, tensile test and wear test. The results revealed that the nanocomposites showed slightly smaller grain size compared to the matrix and uniform distribution of CNTs could achieved at proper content. The addition of CNTs could weaken basal plane texture. Besides, the yield strength and ultimate tensile strength of the composites were enhanced with increase the amount of CNTs up to 2.0wt.%, and reached the maximum values of 241MPa (+28.2%) and 297MPa (6.1%), respectively. But the failure strain was comprised gradually after adding CNTs. Load transfer mechanism, Orowan mechanism and thermal mismatch mechanism played important roles on the enhancement of the yield strength, and several classical models were employed to predict the theoretical values. The reasons attributed to the discrepancy between the theoretical values and experimental values were discussed in details. Besides, the effect of CNTs content on the friction coefficient and weight loss of the nanocomposites were also studied, and the prediction equations were also established by nonlinear fitting. The relationships between the CNTs content and the friction coefficient and weight loss could be described by the exponential decay model and Boltzmann model, respectively.

keywords： Carbon nanotube metal matrix nanocomposites texture strengthening mechanisms wear behavior

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