With ball-bearing and tribofilm lubrication effects, CuO vegetable oil-based nanofluids have exhibited excellent anti-wear and friction reduction properties. In this study, CuO nanofluids were synthesized by a one-step electro discharge process in distilled water containing polysorbate-20 and vegetable oil as a nanoparticle stabilizer and source of fatty-acid molecules in the base fluid, respectively. Pin-on-disk tribotests were conducted to evaluate the lubrication performance of synthesized CuO nanofluids between brass/steel contact pairs under various loadings. Surface grinding experiments under minimum lubrication conditions were also performed to evaluate the effectiveness of the synthesized nanofluids in improving the machining characteristics and surface quality of machined parts. The results of pin-on-disk tests revealed that adding nanofluids containing 0.5% and 1% (mass fraction) CuO nanoparticles to the base fluid reduced the wear rate by 66.7% and 71.2%, respectively, compared with pure lubricant. The lubricating action of 1% (mass fraction) CuO nanofluid reduced the ground surface roughness by up to 30% compared with grinding using lubricant without nano-additives. These effects were attributed to the formation of a lubrication film between the contact pairs, providing the rolling and healing functions of CuO nanoparticles to the sliding surfaces. The micrography of ground surfaces using a scanning electron microscope confirmed the tribological observations.

中文翻译：

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CuO植物油基纳米流体在磨削过程中的摩擦学性能研究

具有滚珠轴承和摩擦膜润滑作用，CuO植物油基纳米流体表现出出色的抗磨损和降低摩擦性能。在这项研究中，CuO纳米流体是通过一步蒸馏法在蒸馏水中合成的，该蒸馏水中分别含有聚山梨酯20和植物油作为纳米颗粒稳定剂和基础液中的脂肪酸分子来源。进行了销盘摩擦试验，以评估各种载荷下黄铜/钢触点对之间合成的CuO纳米流体的润滑性能。还进行了在最小润滑条件下的表面研磨实验，以评估合成纳米流体在改善机械加工特性和机械零件表面质量方面的有效性。针在磁盘上的测试结果表明，与纯润滑剂相比，向基础流体中添加包含0.5％和1％（质量分数）CuO纳米颗粒的纳米流体分别使磨损率降低了66.7％和71.2％。与使用不含纳米添加剂的润滑剂进行研磨相比，1％（质量分数）的CuO纳米流体的润滑作用最多可将地面粗糙度降低30％。这些作用归因于在接触对之间形成润滑膜，从而在滑动表面上提供了CuO纳米颗粒的滚动和修复功能。使用扫描电子显微镜对地面进行显微照相证实了摩擦学的观察结果。与纯润滑剂相比。与使用不含纳米添加剂的润滑剂进行研磨相比，1％（质量分数）的CuO纳米流体的润滑作用最多可将地面粗糙度降低30％。这些作用归因于在接触对之间形成润滑膜，从而在滑动表面上提供了CuO纳米颗粒的滚动和修复功能。使用扫描电子显微镜对地面进行显微照相证实了摩擦学的观察结果。与纯润滑剂相比。与使用不含纳米添加剂的润滑剂进行研磨相比，1％（质量分数）的CuO纳米流体的润滑作用最多可将地面粗糙度降低30％。这些作用归因于在接触对之间形成润滑膜，从而在滑动表面上提供了CuO纳米颗粒的滚动和修复功能。使用扫描电子显微镜对地面进行显微照相证实了摩擦学的观察结果。