Ambient and nitrogen environment friction data for various materials and surface treatments for space applications

A multivariate tribological evaluation of candidate materials, surface treatments and dry film lubricants is necessary for design of moving mechanical components that function reliably in extreme conditions, including for long duration space missions. In this study, linear reciprocating or unidirectional sliding friction data was collected using ball-on-flat tests. The balls were hardened 440C stainless steel (either uncoated or sputtered with MoS2) and flat surfaces were 440C stainless steel, Nitronic 60 stainless steel or Ti6Al4V titanium alloy with various surface treatments and/or dry film lubricants. Surface treatments included anodizing, nitriding and electrical discharge machining. The dry film lubricants included Microseal 200-1 , sputtered MoS2 and a nano-composite coating i-Kote. The data contains applied normal load, measured friction force, calculated coefficient of friction, ball position, ambient temperature and relative humidity during testing. Tests were performed at different peak Hertzian contact pressure conditions ranging from 300 MPa to 2000 MPa. Data is also available for flat surfaces that were vacuum baked at 150 oC after surface treatment and dry film coating as well as samples tested in inert gas (nitrogen) environment. This data can be used both to fundamentally understand the tribological properties of different material systems as well as to enable design of components for specific applications, conditions and duty cycles.针对候选材料、表面处理工艺及干膜润滑剂开展多变量摩擦学评估，对于在极端工况（包括长期太空任务）下可靠运行的运动机械部件设计而言至关重要。本研究采用球-平板（ball-on-flat）摩擦试验，采集了直线往复或单向滑动工况下的摩擦数据。试验用钢球采用淬火态440C不锈钢（未涂层或溅射沉积二硫化钼（MoS₂）涂层），平板试样涵盖440C不锈钢、Nitronic 60不锈钢及Ti6Al4V钛合金，并对其施加各类表面处理工艺及/或干膜润滑剂。所用表面处理工艺包括阳极氧化、氮化及电火花加工；干膜润滑剂包含Microseal 200-1、溅射沉积二硫化钼及纳米复合涂层i-Kote。本数据集涵盖试验过程中记录的施加法向载荷、实测摩擦力、计算得到的摩擦系数、钢球位置、环境温度及相对湿度。试验在峰值赫兹接触（Hertzian contact）压力300 MPa至2000 MPa的不同工况下开展。此外，数据集还包含经表面处理与干膜涂层后在150℃真空烘烤的平板试样数据，以及在惰性气体（氮气）环境中完成测试的试样数据。该数据集既可用于从基础层面解析不同材料体系的摩擦学特性，也可为特定应用场景、工况及负载循环的部件设计提供支撑。