- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Improving processing quality and tribological behavior of laser surface textures using oil layer method
摘要： The study proposes an effective oil layer method for improving the processing quality and the tribological behavior of laser textured surface. Experimental results suggest the oil layer method has the reduction effect on the coverage area of metallic oxide and the height of rim ridges/burrs of textures. Possible mechanisms are mainly attributed as: i) the cooling down effect of oil flow; ii) the protecting of oil film to reduce oxidation and adhesion of laser-ablated melt on metal surface. Moreover, tribological tests confirm the favorable effect of textures laser-irradiated using the oil layer method on reducing friction coefficient.
关键词： surface textures,oil layer method,tribological behavior,laser processing
更新于2025-09-19 17:13:59
-
Enhanced wear resistance and new insight into microstructure evolution of in-situ (Ti,Nb)C reinforced 316??L stainless steel matrix prepared via laser cladding
摘要： An MC (M: Ti,Nb) carbide-reinforced 316 L coating was synthesized in-situ via laser cladding. A strong relationship between the (Ti,Nb)C content and the microstructure and tribological properties of the resulting components was established. This relationship helped explain the in?uence of the (Ti,Nb)C content on the phase evolution, microstructure characteristics, and exothermic reaction behavior. It was found that the size and morphology of in-situ generated (Ti,Nb)C particles changed as the carbide content increased. When the MC carbide content increased from 2.5 wt% to 10 wt%, the morphology of in-situ generated (Ti,Nb)C evolved from irregular geometry particles, to spherical particles, and ?nally into near-regular geometry. When the carbide content reached 15 wt%, the (Ti,Nb)C particles displayed an equilibrium octahedral structure. The calculated formation enthalpy of MC carbides showed that the reaction enthalpy increased with the MC carbide content, which a?ected the dynamic temperature of the molten pool and eventually led to carbides with di?erent crystal morphologies and sizes. Room-temperature dry sliding friction and wear tests showed that the submicron (Ti,Nb)C carbide reinforced (carbide content: 5 wt%) coating and 1.5 ??m regular octahedral particle-reinforced coating (carbide content: 20 wt%) exhibited a lower friction coe?cient and wear volume loss. Understanding the morphological evolution mechanism of (Ti,Nb)C and its corresponding tribological behavior will enable the development of guidelines to obtain (Ti,Nb)C/316 L metal matrix composite coatings produced by laser cladding.
关键词： (Ti,Nb)C,Laser cladding,Tribological behavior,Microstructure,In-situ
更新于2025-09-16 10:30:52
-
Effect of the surface texturing treatment with Nd: YAG laser on the wear resistance of CoCr alloy
摘要： The present work aims to explore the tribological behavior of the laser texturing process with different patterns on a Co based alloy using a pulsed Nd: YAG laser. Different parameters such as peak power, speed and spot diameter of the laser were explored for the experimental setting. The microstructural analysis was performed using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and nanoindentation tests. The influence of the different textured patterns of the tribological performance tested with a pin-on-disc tribometer under lubricated sliding condition was evaluated. The results showed that typical interdendritic structures in the as-cast CoCr alloy condition were refined due to the heat input and fast cooling rate during the laser treatment. The refined microstructure showed less volumetric loss resulting in a increment of wear resistance and a better tribological performance than as-cast alloy. The correlation among laser parameters, microstructural effect and their influence in wear resistance is discussed.
关键词： Nd: YAG laser,laser texturing,CoCr alloy,tribological behavior,wear resistance
更新于2025-09-12 10:27:22
-
Reactive Fabrication and Effect of NbC on Microstructure and Tribological Properties of CrS Co-Based Self-Lubricating Coatings by Laser Cladding
摘要： The CrS/NbC Co-based self-lubricating composite coatings were successfully fabricated on Cr12MoV steel surface by laser clad Stellite 6, WS2, and NbC mixed powders. The phase composition, microstructure, and tribological properties of the coatings ware investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS), as well as dry sliding wear testing. Based on the experimental results, it was found reactions between WS2 and Co-based alloy powder had occurred, which generated solid-lubricant phase CrS, and NbC play a key role in improving CrS nuclear and re?ning microstructure of Co-based composite coating during laser cladding processing. The coatings were mainly composed of γ-Co, CrS, NbC, Cr23C6, and CoCx. Due to the distribution of the relatively hard phase of NbC and the solid lubricating phase CrS, the coatings had better wear resistance. Moreover, the suitable balance of CrS and NbC was favorable for further decreasing the friction and improving the stability of the contact surfaces between the WC ball and the coatings. The microhardness, friction coef?cient, and wear rate of the coating 4 (Clad powders composed of 60 wt % Stellite 6, 30 wt % NbC and 10 wt % WS2) were 587.3 HV0.5, 0.426, and 5.61 × 10?5 mm3/N·m, respectively.
关键词： tribological behavior,metal matrix self-lubricating coating,laser cladding,microstructure
更新于2025-09-10 09:29:36
-
On the formation features, structure, microhardness and tribological behavior of single tracks and coating layers formed by laser cladding of Al-Fe powder bronze
摘要： In this paper, the effect of the gas flow and pressure on the powder flow, as well as the effect of the conditions of laser cladding on the microstructure, phase composition, microhardness and tribological behavior of an Al-Fe powder bronze coating, is studied. The features of single tracks, single- and double-layer coatings are described. The speed of a laser beam, the pitch of the single track and the distance between the nozzle and the coated surface affect the microstructure and microhardness of the coating. These parameters are more stable for double-layer coatings because a denser coating with better fusing along the grain boundaries is formed as a result of secondary melting. Under dry friction conditions, with deposition speeds less than 140–160 mm/min, the coefficient of the friction is stable and significantly lower compared with cast aluminium bronzes. In such conditions, the wear resistance of the coating increases with the increase in deposition speed. With further speed increases, a substantial rise in the friction coefficient in time and a substantial seizure of friction surfaces are observed. Under lubricated friction conditions, when the load increases from 120 N to 360 N, that is, where the pressure on the contact surface increases from 1.75 to 5.3 MPa, a sharp increase in the wear rate occurs with a deposition speed of 120 mm/min almost 130-fold and for a speed of 140 mm/min ~9-fold.
关键词： Al-Fe bronze,Powder flow,Single- and double-layer coating features,Laser cladding,Tribological behavior,Single track features
更新于2025-09-09 09:28:46