A structural model of a soft/hard compositecoated textured (SHCCT) tool was proposed and substantiated by a three-dimensional numerical simulation. Its dry turning performance as applied to AISI-1045 steel was analyze...A structural model of a soft/hard compositecoated textured (SHCCT) tool was proposed and substantiated by a three-dimensional numerical simulation. Its dry turning performance as applied to AISI-1045 steel was analyzed via three-factor five-level orthogonal experiments for different coating parameters, including coating thickness, coating material, and thickness ratio of the soft and hard coatings. In addition, the cutting performance of the proposed SHCCT tool was compared with those of uncoated non-textured, coated non?textured, and uncoated textured tools, and its superiority was proved by the significant reductions in the cutting force, and specifically, the cutting temperature. The optimal results were provided by the SHCCT tool with a WS2/ZrN soft/hard composite coating, a 0.9:0.1 thickness ratio of the above ingredients, and a total coating thickness of 0.5 μm.展开更多
基于Reynolds方程和P-C(Patir and Cheng)模型,分别建立了织构表面在流体动压润滑及混合润滑状态下的理论模型。采用有限差分法并结合数值迭代,利用Matlab编程对模型进行计算,获得计算域内的压力分布和织构表面的理论摩擦系数,以此作为...基于Reynolds方程和P-C(Patir and Cheng)模型,分别建立了织构表面在流体动压润滑及混合润滑状态下的理论模型。采用有限差分法并结合数值迭代,利用Matlab编程对模型进行计算,获得计算域内的压力分布和织构表面的理论摩擦系数,以此作为织构表面摩擦学性能的判断标准。采用飞秒激光加工工艺,在氧化锆(ZrO_2)增强HA(Hydroxyapatite,羟基磷灰石)生物陶瓷涂层表面,加工出具有不同排布方式的椭圆形织构阵列和不同面覆率的圆形织构阵列。在往复实验平台进行摩擦磨损实验,利用三维轮廓仪表征涂层的磨损深度,并验证了数值模型。展开更多
Titanium alloys are poor in wear resistance and it is not suitable under sliding conditions even with lubrication because ofits severe adhesive wear tendency.The surface modifications through texturing and surface coa...Titanium alloys are poor in wear resistance and it is not suitable under sliding conditions even with lubrication because ofits severe adhesive wear tendency.The surface modifications through texturing and surface coating were used to enhance the surfaceproperties of the titanium alloy substrate.Hard and wear resistant coatings such as TiAlN and AlCrN were applied over texturedtitanium alloy surfaces with chromium as interlayer.To improve the friction and wear resisting performance of hard coatings further,solid lubricant,molybdenum disulphide(MoS2),was deposited on dimples made over hard coatings.Unidirectional sliding weartests were performed with pin on disc contact geometry,to evaluate the tribological performance of coated substrates.The tests wereperformed under three different normal loads for a period of40min at sliding velocity of2m/s.The tribological behaviours ofmulti-layer coatings such as coating structure,friction coefficient and specific wear rate were investigated and analyzed.The lowerfriction coefficient of approximately0.1was found at the early sliding stage,which reduces the material transfer and increases thewear life.Although,the friction coefficient increased to high values after MoS2coating was partially removed,substrate was stillprotected against wear by underlying hard composite layer.展开更多
基金the National Natural Science Foundation of China (Grant No. 51505399)the Natural Science Foundation of Fujian Province of China (Grant No. 2017J05088)the Fundamental Research Funds for the Central Universities, Xiamen University (Grant No. 20720160078).
文摘A structural model of a soft/hard compositecoated textured (SHCCT) tool was proposed and substantiated by a three-dimensional numerical simulation. Its dry turning performance as applied to AISI-1045 steel was analyzed via three-factor five-level orthogonal experiments for different coating parameters, including coating thickness, coating material, and thickness ratio of the soft and hard coatings. In addition, the cutting performance of the proposed SHCCT tool was compared with those of uncoated non-textured, coated non?textured, and uncoated textured tools, and its superiority was proved by the significant reductions in the cutting force, and specifically, the cutting temperature. The optimal results were provided by the SHCCT tool with a WS2/ZrN soft/hard composite coating, a 0.9:0.1 thickness ratio of the above ingredients, and a total coating thickness of 0.5 μm.
文摘基于Reynolds方程和P-C(Patir and Cheng)模型,分别建立了织构表面在流体动压润滑及混合润滑状态下的理论模型。采用有限差分法并结合数值迭代,利用Matlab编程对模型进行计算,获得计算域内的压力分布和织构表面的理论摩擦系数,以此作为织构表面摩擦学性能的判断标准。采用飞秒激光加工工艺,在氧化锆(ZrO_2)增强HA(Hydroxyapatite,羟基磷灰石)生物陶瓷涂层表面,加工出具有不同排布方式的椭圆形织构阵列和不同面覆率的圆形织构阵列。在往复实验平台进行摩擦磨损实验,利用三维轮廓仪表征涂层的磨损深度,并验证了数值模型。
文摘Titanium alloys are poor in wear resistance and it is not suitable under sliding conditions even with lubrication because ofits severe adhesive wear tendency.The surface modifications through texturing and surface coating were used to enhance the surfaceproperties of the titanium alloy substrate.Hard and wear resistant coatings such as TiAlN and AlCrN were applied over texturedtitanium alloy surfaces with chromium as interlayer.To improve the friction and wear resisting performance of hard coatings further,solid lubricant,molybdenum disulphide(MoS2),was deposited on dimples made over hard coatings.Unidirectional sliding weartests were performed with pin on disc contact geometry,to evaluate the tribological performance of coated substrates.The tests wereperformed under three different normal loads for a period of40min at sliding velocity of2m/s.The tribological behaviours ofmulti-layer coatings such as coating structure,friction coefficient and specific wear rate were investigated and analyzed.The lowerfriction coefficient of approximately0.1was found at the early sliding stage,which reduces the material transfer and increases thewear life.Although,the friction coefficient increased to high values after MoS2coating was partially removed,substrate was stillprotected against wear by underlying hard composite layer.
