Tungsten, molybdenum and cobalt were co-diffused into the surface of ingot, 20 steel, 45 steel and T8 steel by a double glow plasma surface alloying technique. Surface alloyed layers formed on ingot and 20 steel are c...Tungsten, molybdenum and cobalt were co-diffused into the surface of ingot, 20 steel, 45 steel and T8 steel by a double glow plasma surface alloying technique. Surface alloyed layers formed on ingot and 20 steel are composed of -Fe +(Fe,Co)7(W,Mo)6, which possess the same strong age-hardening ability as the metallurgical age-hardened high speed steel, the maximum hardness can reach 1100 HV0.o25 after ageing treatment. Surface alloyed layers formed on 45 steel and T8 steel are composed of M6C, hardness of which are over 1100-1400 HV0.o25- Alloyed layers formed on ingot and 20 steel possess good toughness. Alloyed layer of carbide type exhibits slightly brittleness.展开更多
Arc-added glow discharge plasma penetrating technique is a new surface coating method. With the help of vacuum arc discharge, a cold cathode arc source continually emits ion beams of coating elements with high currenc...Arc-added glow discharge plasma penetrating technique is a new surface coating method. With the help of vacuum arc discharge, a cold cathode arc source continually emits ion beams of coating elements with high currency density and high ionizing ratio. As the ion bombard and diffusion working on, the surface of the parts form deposited layer, penetrated layer and hybrid layer. Under lab condition, a commercial magnesium alloy Az91 had been coated with Ti film layer with the aim of improving its’ anti-corrosion performance. This paper mainly summarized our studies on the testing and analyzing of the coating layer. The composition and microstructure of the coating layer had been analyzed by means of X-ray diffraction (XRD) and glow discharge spectrum (GDS), and the surface appearance had been surveyed by scanning electronic microscope (SEM). The adhesion strength between film and matrix had been evaluated by experiments of sticking-tearing. The results indicated that the coated layer on magnesium alloy were homogeneous, dense and robustly adhered.展开更多
A new net-shape cathode sputtering target which has a simple structure and a hig h sputtering was put forward. The multiple-structure made of alloying and coatin g layers of tantalum was achieved on the surface of TC4...A new net-shape cathode sputtering target which has a simple structure and a hig h sputtering was put forward. The multiple-structure made of alloying and coatin g layers of tantalum was achieved on the surface of TC4 (Ti6Al4V) using this met hod in double glow surface alloying process. The tantalized samples were investi gated by SEM, XRD and electrochemical corrosion method .Results show the complic ated tissue of pure tantalizing layer and diffusion layer was successfully forme d on the surface of TC4 with the method of net-shape cathode glow discharge, whi ch further improved the corrosion-resistance of TC4 and formed good corrosion-re sistant alloys.展开更多
A model is developed for predicting the correlation between processing parameters and the technical target of double glow by applying artificial neural network (ANN). The input parameters of the neural network (NN) ar...A model is developed for predicting the correlation between processing parameters and the technical target of double glow by applying artificial neural network (ANN). The input parameters of the neural network (NN) are source voltage, workplace voltage, working pressure and distance between source electrode and workpiece. The output of the NN model is three important technical targets, namely the gross element content, the thickness of surface alloying layer and the absorption rate (the ratio of the mass loss of source materials to the increasing mass of workpiece) in the processing of double glow plasma surface alloying. The processing parameters and technical target are then used as a training set for an artificial neural network. The model is based on multiplayer feedforward neural network. A very good performance of the neural network is achieved and the calculated results are in good agreement with the experimental ones.展开更多
The Ni-Cr-Mo-Cu multi-element surface alloying with the electric brushplating Ni interlayer on the low carbon steel substrate has been investigated. By theelectrochemical method in 3.5 percent (mass fraction) NaCl sol...The Ni-Cr-Mo-Cu multi-element surface alloying with the electric brushplating Ni interlayer on the low carbon steel substrate has been investigated. By theelectrochemical method in 3.5 percent (mass fraction) NaCl solution, the corrosion resistance of thecomposite alloying layer and single alloying layer is determined. The experimental results showthat the corrosion resistance of the composite alloying layer is obviously better than that of thesingle alloying layer. The structure and composition of passive films formed on the two kinds ofalloyed layers after electrochemical tests in 3.5 percent NaCl solution have been studied usingX-ray photoelectron spectroscopy (XPS). It is concluded that the double glow plasma surface alloyingof low carbon steel with the electric brush plating Ni interlayer is an appropriate technique toenhance the corrosion resistance compared with the single double glow surface alloying.展开更多
基金supported by the Natural Science Foundation of Shanxi Province under Contract Number 20021054the Youth Science Foundation of Taiyuan University of Technology under Contract Number 190-100003.
文摘Tungsten, molybdenum and cobalt were co-diffused into the surface of ingot, 20 steel, 45 steel and T8 steel by a double glow plasma surface alloying technique. Surface alloyed layers formed on ingot and 20 steel are composed of -Fe +(Fe,Co)7(W,Mo)6, which possess the same strong age-hardening ability as the metallurgical age-hardened high speed steel, the maximum hardness can reach 1100 HV0.o25 after ageing treatment. Surface alloyed layers formed on 45 steel and T8 steel are composed of M6C, hardness of which are over 1100-1400 HV0.o25- Alloyed layers formed on ingot and 20 steel possess good toughness. Alloyed layer of carbide type exhibits slightly brittleness.
文摘Arc-added glow discharge plasma penetrating technique is a new surface coating method. With the help of vacuum arc discharge, a cold cathode arc source continually emits ion beams of coating elements with high currency density and high ionizing ratio. As the ion bombard and diffusion working on, the surface of the parts form deposited layer, penetrated layer and hybrid layer. Under lab condition, a commercial magnesium alloy Az91 had been coated with Ti film layer with the aim of improving its’ anti-corrosion performance. This paper mainly summarized our studies on the testing and analyzing of the coating layer. The composition and microstructure of the coating layer had been analyzed by means of X-ray diffraction (XRD) and glow discharge spectrum (GDS), and the surface appearance had been surveyed by scanning electronic microscope (SEM). The adhesion strength between film and matrix had been evaluated by experiments of sticking-tearing. The results indicated that the coated layer on magnesium alloy were homogeneous, dense and robustly adhered.
文摘A new net-shape cathode sputtering target which has a simple structure and a hig h sputtering was put forward. The multiple-structure made of alloying and coatin g layers of tantalum was achieved on the surface of TC4 (Ti6Al4V) using this met hod in double glow surface alloying process. The tantalized samples were investi gated by SEM, XRD and electrochemical corrosion method .Results show the complic ated tissue of pure tantalizing layer and diffusion layer was successfully forme d on the surface of TC4 with the method of net-shape cathode glow discharge, whi ch further improved the corrosion-resistance of TC4 and formed good corrosion-re sistant alloys.
文摘A model is developed for predicting the correlation between processing parameters and the technical target of double glow by applying artificial neural network (ANN). The input parameters of the neural network (NN) are source voltage, workplace voltage, working pressure and distance between source electrode and workpiece. The output of the NN model is three important technical targets, namely the gross element content, the thickness of surface alloying layer and the absorption rate (the ratio of the mass loss of source materials to the increasing mass of workpiece) in the processing of double glow plasma surface alloying. The processing parameters and technical target are then used as a training set for an artificial neural network. The model is based on multiplayer feedforward neural network. A very good performance of the neural network is achieved and the calculated results are in good agreement with the experimental ones.
文摘The Ni-Cr-Mo-Cu multi-element surface alloying with the electric brushplating Ni interlayer on the low carbon steel substrate has been investigated. By theelectrochemical method in 3.5 percent (mass fraction) NaCl solution, the corrosion resistance of thecomposite alloying layer and single alloying layer is determined. The experimental results showthat the corrosion resistance of the composite alloying layer is obviously better than that of thesingle alloying layer. The structure and composition of passive films formed on the two kinds ofalloyed layers after electrochemical tests in 3.5 percent NaCl solution have been studied usingX-ray photoelectron spectroscopy (XPS). It is concluded that the double glow plasma surface alloyingof low carbon steel with the electric brush plating Ni interlayer is an appropriate technique toenhance the corrosion resistance compared with the single double glow surface alloying.
