中频磁控溅射沉积梯度过渡Cr/CrN/CrNC/CrC膜的附着性能

采用中频磁控溅射结合无灯丝离子源技术沉积梯度Cr/CrN/CrNC/CrC膜层,设计两组正交实验对膜层中界面Cr层及梯度层沉积的工艺参数对附着性能的影响进行研究。利用扫描电镜（SEM）、电子能谱（EDS）对其表面形貌及梯度成分进行表征;用划痕仪、显微硬度计及洛氏硬度计测评其附着性能,并对比两者测评的有效性。所得最优工艺参数为：梯度层沉积偏压100 V,中频功率6.5 kW,真空度0.6 Pa;Cr层的沉积时间、离子源电流及中频功率分别为2 min、4 A和6.5 kW。高中频功率及离子辅助沉积Cr层能有效提高膜层附着力。     

CrC复合镀层钢球对轴承振动性能的影响

应用非平衡磁控溅射技术在6204轴承钢球表面制备出CrC复合镀层,对CrC镀层钢球轴承和无镀层钢球轴承的振动性能进行试验及对比分析。结果表明,CrC镀层钢球轴承明显降低了轴承的振动值,特别是在高速、高载荷工况情况下减振效果尤为显著;提高了轴承振动的平稳性能。     

磁控溅射CrC复合镀层对轴承性能可靠性的影响

应用非平衡磁控溅射离子镀技术在6204轴承钢球表面制备出CrC复合镀层,并对CrC镀层轴承和无镀层轴承的性能可靠性进行了实验及其对比分析。研究结果表明,采用平衡磁控溅射离子镀技术制备的CrC复合镀层质量优异;CrC镀层钢球轴承明显降低了轴承的振动值,提高了振动的稳定性和抗温变性能,具有良好的性能可靠性。     

铬掺杂碳基自润滑薄膜与铝合金的高温磨损机理

为了研究不同结构铬掺杂碳基薄膜在高温下与铝合金的磨损机理,采用非平衡磁控溅射在YT15刀具表面沉积Cr/CrC/DLC单周期和Cr/(CrC-DLC)_n多周期多层膜,在24、200和400℃下与A319和A390铝合金进行摩擦试验。采用扫描电子显微镜、原子力显微镜、纳米压痕仪、拉曼光谱仪、销盘磨损仪对薄膜的形貌结构、力学和摩擦学性能进行测试。研究表明:多周期多层膜结构打断薄膜柱状生长,提高膜基结合力。两种薄膜表面粗糙度和硬度分别为4.3 nm和5.4 nm、9.8 GPa和9.0 GPa。磨球表面转移层由硅、石墨以及剥落的薄膜碎片组成,连续的转移层降低摩擦因数;但随着温度升高,转移层的连续性被破坏,导致摩擦因数升高。在高温摩擦过程中,多周期多层膜磨损逐渐释放出DLC子膜层,通过DLC子膜层的石墨化转变来保持低摩擦因数,提高薄膜寿命。薄膜磨损由室温的磨料磨损转变为高温的粘着磨损和犁沟磨损,其中由于A390含有初晶硅使磨损以犁沟磨损为主。     

Thermal stability of nanocomposite CrC/a-C:H thin films

The thermal stability of low-friction Me-C/a-C:H coatings is important for their potential applications in the tool and automotive industry. Recently we showed that CrC_x/a-C:H coatings prepared by unbalanced magnetron sputtering of a Cr target in Ar + CH₄ glow discharges exhibit a nanocomposite structure where metastable fcc CrC nanocrystals are encapsulated by an a-C:H phase. Here, we present the structural evolution of these nanocomposite CrC/a-C:H coatings during annealing. High-temperature X-ray diffraction in vacuum and differential scanning calorimetry (DSC) combined with thermo-gravimetric analysis in Ar atmosphere indicate decomposition of the formed metastable fcc CrC phase and subsequent formation of Cr₃C₂ and Cr₇C₃ and structural transformation of the a-C:H matrix phase towards higher sp² bonding contents at temperatures above 450 °C. Combined DSC and mass spectrometer analysis as well as elemental profiling after annealing in vacuum by elastic recoil detection analysis relate this transformation to the loss of bonded hydrogen at temperatures above 200 °C.Due to these structural changes the coefficient of friction depends on the annealing temperature of the nanocomposite a-C:H coatings and shows a minimum of ∼ 0.13 for T = 200 °C. The more complex tribochemical reactions, influenced by the hydrogen loss from the coating during in-situ high temperatures ball-on disc tests, result in coefficient of friction values below 0.05 for T < 120 °C.