Titanium carbonitride (TiCN) coating was prepared on 45# carbon steel by electrical discharge coating (EDC), and the compositions, morphology and microstructure of the coating were studied. In addition, its friction a...Titanium carbonitride (TiCN) coating was prepared on 45# carbon steel by electrical discharge coating (EDC), and the compositions, morphology and microstructure of the coating were studied. In addition, its friction and wear behaviors relative to the physical vapor deposition (PVD) TiN coating were investigated. The results show that the TiCN coating features a thickness of 15μm with a primary phase of TiC 0.3 N 0.7 . The wear rates of the two coatings have no clear distinction at low applied loads. However, severe abrasive wear appears in the PVD TiN coating when the applied load exceeds 30 N, while the TiCN coating features better wear resistance. The abrasive wear with coating peelings is found to be the predominant wear mechanism at high applied loads.展开更多
Hard coatings are extensively required in industry for protecting mechanical/structural parts that withstand extremely high temperature,stress,chemical corrosion,and other hostile environments.Electrical discharge coa...Hard coatings are extensively required in industry for protecting mechanical/structural parts that withstand extremely high temperature,stress,chemical corrosion,and other hostile environments.Electrical discharge coating(EDC)is an emerging surface modification technology to produce such hard coatings by using electrical discharges to coat a layer of material on workpiece surface to modify and enhance the surface characteristics or create new surface functions.This paper presents a comprehensive overview of EDC technologies for various materials,and summarises the types and key parameters of EDC processes as well as the characteristics of resulting coatings.It provides a systematic summary of the fundamentals and key features of the EDC processes,as well as its applications and future trends.展开更多
The method of electrical discharge coating with TiC ceramic layer in ordinary electrical discharge machining(EDM) tool was studied systematically. Through the metallography, X-ray diffraction, sector scanning research...The method of electrical discharge coating with TiC ceramic layer in ordinary electrical discharge machining(EDM) tool was studied systematically. Through the metallography, X-ray diffraction, sector scanning research and wear test, the characteristics of the ceramic layer were studied, and the effect of the discharge parameters on the quality and the thickness of the coating was also discussed. The results show that this method is a very potential surface modification method. Comparing with other surface peeling technologies, that coating layer thickness is more than 20μm, the hardness is increased by 2-3 times, the wearing resistance is increased by 5 times and the product life is increased by 3-5 times.展开更多
This paper describes a new method of surface modification by Electrical Discharge Machining (EDM). By using ordinary EDM machine tool and kerosene fluid, a hard ceramic layer can be created on the workpiece surface wi...This paper describes a new method of surface modification by Electrical Discharge Machining (EDM). By using ordinary EDM machine tool and kerosene fluid, a hard ceramic layer can be created on the workpiece surface with Ti or other compressed powder electrode in a certain condition. This new revolutionary method is called Electrical Discharge Coating (EDC). The process of EDC begins with electrode wear during EDM,then a kind of hard carbide is created through the thermal and chemical reaction between the worn electrode material and the carbon particle decomposed from kerosene fluid under high temperature. The carbide is piled up on a workpiece quickly and becomes a hard layer of ceramic about 20 μm in several minutes. This paper studies the principle and process of EDC systemically by using Ti powder green compact electrode. In order to obtain a layer of compact ceramic film, it is very important to select proper electric pulse parameters, such as pulse width, pulse interval, peak current. Meantime, the electrode materials and its forming mode will effect the machining surface quality greatly. This paper presents a series of experiment results to study the EDC process by adopt different technology parameters. Experiments and analyses show that a compact TiC ceramic layer can be created on the surface of metal workpiece. The hardness of ceramic layer is more 3 times higher than the base body, and the hardness changes gradiently from surface to base body. The method will have a great future because many materials can be easily added to the electrode and then be coated on the workpiece surface. Gearing the parameters ceramic can be created with different thickness. The switch between deposition and removal process is carried out easily by changing the polarity, thus the gear to the thickness and shape of the composite ceramic layer is carried out easily. This kind of composite ceramic layer will be used to deal with the surface of the cutting tools or molds possibly, in order to lengthen their life. It also can be found wide application in the fields of surface repairing and strengthening of the ship or aircraft.展开更多
基金Project(51075075)supported by the National Natural Science Foundation of China
文摘Titanium carbonitride (TiCN) coating was prepared on 45# carbon steel by electrical discharge coating (EDC), and the compositions, morphology and microstructure of the coating were studied. In addition, its friction and wear behaviors relative to the physical vapor deposition (PVD) TiN coating were investigated. The results show that the TiCN coating features a thickness of 15μm with a primary phase of TiC 0.3 N 0.7 . The wear rates of the two coatings have no clear distinction at low applied loads. However, severe abrasive wear appears in the PVD TiN coating when the applied load exceeds 30 N, while the TiCN coating features better wear resistance. The abrasive wear with coating peelings is found to be the predominant wear mechanism at high applied loads.
基金Pay Jun Liew and Ching Yee Yap acknowledge the supportsfrom Universiti Teknikal Malaysia Melaka (UTeM) for thetechnical and financial supports through the grant PJP/2018/FKP(6A)/S01587.
文摘Hard coatings are extensively required in industry for protecting mechanical/structural parts that withstand extremely high temperature,stress,chemical corrosion,and other hostile environments.Electrical discharge coating(EDC)is an emerging surface modification technology to produce such hard coatings by using electrical discharges to coat a layer of material on workpiece surface to modify and enhance the surface characteristics or create new surface functions.This paper presents a comprehensive overview of EDC technologies for various materials,and summarises the types and key parameters of EDC processes as well as the characteristics of resulting coatings.It provides a systematic summary of the fundamentals and key features of the EDC processes,as well as its applications and future trends.
文摘The method of electrical discharge coating with TiC ceramic layer in ordinary electrical discharge machining(EDM) tool was studied systematically. Through the metallography, X-ray diffraction, sector scanning research and wear test, the characteristics of the ceramic layer were studied, and the effect of the discharge parameters on the quality and the thickness of the coating was also discussed. The results show that this method is a very potential surface modification method. Comparing with other surface peeling technologies, that coating layer thickness is more than 20μm, the hardness is increased by 2-3 times, the wearing resistance is increased by 5 times and the product life is increased by 3-5 times.
文摘This paper describes a new method of surface modification by Electrical Discharge Machining (EDM). By using ordinary EDM machine tool and kerosene fluid, a hard ceramic layer can be created on the workpiece surface with Ti or other compressed powder electrode in a certain condition. This new revolutionary method is called Electrical Discharge Coating (EDC). The process of EDC begins with electrode wear during EDM,then a kind of hard carbide is created through the thermal and chemical reaction between the worn electrode material and the carbon particle decomposed from kerosene fluid under high temperature. The carbide is piled up on a workpiece quickly and becomes a hard layer of ceramic about 20 μm in several minutes. This paper studies the principle and process of EDC systemically by using Ti powder green compact electrode. In order to obtain a layer of compact ceramic film, it is very important to select proper electric pulse parameters, such as pulse width, pulse interval, peak current. Meantime, the electrode materials and its forming mode will effect the machining surface quality greatly. This paper presents a series of experiment results to study the EDC process by adopt different technology parameters. Experiments and analyses show that a compact TiC ceramic layer can be created on the surface of metal workpiece. The hardness of ceramic layer is more 3 times higher than the base body, and the hardness changes gradiently from surface to base body. The method will have a great future because many materials can be easily added to the electrode and then be coated on the workpiece surface. Gearing the parameters ceramic can be created with different thickness. The switch between deposition and removal process is carried out easily by changing the polarity, thus the gear to the thickness and shape of the composite ceramic layer is carried out easily. This kind of composite ceramic layer will be used to deal with the surface of the cutting tools or molds possibly, in order to lengthen their life. It also can be found wide application in the fields of surface repairing and strengthening of the ship or aircraft.
