ABSTRACT

Zn-Cu alloys have been considered as potential candidates for bioimplant applications due to their moderate corrosion rate and admirable mechanical properties with non-toxic nature to the human body. However, with the incorporation of advanced reinforcements, such as carbon allotropes, the properties and applicability of a Zn-Cu alloy matrix can be further enhanced. In this research, graphene (Gr) nanoplatelets reinforced Zn-Cu/Gr nanocomposites were synthesised through a modified electro-codeposition method with different concentrations of Gr (25, 50 and 100 mg L⁻¹) in the electrolyte bath. The prepared powder samples were compacted and sintered to form pellets. The pellets were tested for mechanical and in-vitro corrosion. The obtained micro-hardness, compressive yield strength (CYS) and ultimate compressive strength (UCS) of Zn-Cu/Gr (100 mg L⁻¹) nanocomposite are 151 HV, 340 MPs and 362 MPa with increments of 84.1%, 118% and 70.7% compared to pure Zn-Cu alloy, respectively. The reduced wear rates and friction coefficients of Zn-Cu/Gr nanocomposites are attributed to crystallite size refinement and Gr content. The electrochemical corrosion rate is reduced by 66.6% from 33 × 10⁻³ mm year⁻¹ for pure Zn-Cu alloy to 11 × 10⁻³ mm year⁻¹ for Zn-Cu/Gr (100 mg L⁻¹) nanocomposites, owing to Gr barrier protection. The in-vitro cytotoxicity assessment reveals that the prepared Zn-Cu/Gr nanocomposite is non-toxic for Gr concentration up to 50 mg L⁻¹ in the electrolyte bath. The results show that a non-toxic Zn-Cu/Gr nanocomposite with outstanding tribo-mechanical and anti-corrosion properties can be synthesised by the proposed method.

摘要

Zn-Cu 合金由于其适度的腐蚀速率和令人钦佩的机械性能以及对人体无毒的性质，被认为是生物植入应用的潜在候选材料。然而，通过加入先进的增强材料，如碳同素异形体，可以进一步增强 Zn-Cu 合金基体的性能和适用性。在这项研究中，石墨烯 (Gr) 纳米片增强的 Zn-Cu/Gr 纳米复合材料通过改进的电共沉积方法在电解质浴中使用不同浓度的 Gr（25、50 和 100 mg L ^-1）合成。将制备的粉末样品压实并烧结以形成丸粒。颗粒经过机械和体外测试腐蚀。Zn-Cu/Gr（100 mg L ^-1）纳米复合材料的显微硬度、压缩屈服强度（CYS）和极限压缩强度（UCS）分别为151 HV、340 MPs和362 MPa，增量分别为84.1%、118%与纯 Zn-Cu 合金相比分别为 70.7% 和 70.7%。Zn-Cu/Gr 纳米复合材料的磨损率和摩擦系数降低归因于微晶尺寸细化和 Gr 含量。电化学腐蚀速率从纯 Zn-Cu 合金的33 × 10 ^-3  mm year ^-1降低到Zn-Cu/Gr (100 mg L ^-1 ) 纳米复合材料的11 × 10 ^-3  mm year ^-1降低了 66.6% ，由于 Gr 屏障保护。在体外细胞毒性评估表明，所制备的 Zn-Cu/Gr 纳米复合材料对于电解质浴中高达 50 mg L ^{-1 的}Gr 浓度是无毒的。结果表明，该方法可以合成具有优异摩擦力学和抗腐蚀性能的无毒Zn-Cu/Gr纳米复合材料。