Structural changes of thermal sprayed graphene nano platelets film into amorphous carbon under sliding wear
Structural changes of thermal sprayed graphene nano platelets film into amorphous carbon under sliding wear
复制标题
DOI：
10.1016/j.apsusc.2020.146315
复制
发表时间：
2020-10-30
影响因子：
6.7
通讯作者：
Hussain, T.
中科院分区：
文献类型：
--
作者：
Derelizade, K.;Venturi, F.;Hussain, T.
由于其强度和润滑能力，石墨烯已成为保护表面免受摩擦的有希望的候选者。在本研究中，通过高速氧燃料热喷枪向轴向喷射GNP悬浮液，将石墨烯纳米片（GNP）薄膜沉积在不锈钢基体上。在5 N载荷作用下，通过无润滑球对烧结氧化铝对抗体球的摩擦磨损试验，研究了膜在干滑动磨损下的摩擦学性能。了解GNPs在滑动磨损下的行为将有助于提高石墨烯基涂层的性能，从而满足耐磨应用的需求。与未涂覆的不锈钢相比，即使是不连续的薄膜，其摩擦系数值也降低了7倍。形态学分析表明，滑动磨损导致颗粒形状从棱角分明的片状变为随机取向的圆形。原子间键合和结构分析揭示了磨损试验中氧化缺陷的形成。在此过程中，GNPs的结构降解和氧化导致石墨烯形成无定形碳。非晶碳的形成降低了薄膜的润滑能力和强度，导致失效。
Graphene has become a promising candidate to protect surfaces against friction due to its strength and lubricating ability. In this study, graphene nano platelets (GNP) thin films have been deposited onto stainless steel substrates by axially injecting GNP suspension through high velocity oxy fuel thermal spray gun. The tribological performance of the films under dry sliding wear was investigated through unlubricated ball on disc sliding wear test against a sintered alumina counter body ball under 5 N load. The understanding of the behaviour of the GNPs under sliding wear will be useful for improving the performance of graphene-based coatings which are in demand for wear resistant applications. A film was deposited showing significant improvements in friction with coefficient of friction value reduced by 7 times compared to uncoated stainless steel, even for a discontinuous film. A morphological analysis shows sliding wear led to change in particle shape from angular flakes into randomly oriented circles. Interatomic bonding and structural analysis performed reveals oxidation defect formations during wear test. Structural degradation and oxidation of GNPs during the process led to formation of amorphous carbon from graphene. Amorphous carbon formation reduces the lubricating ability and strength of the film, leading to failure.