An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is developed and the details of its construction and operation are reported. Using high purity SiH4 and GeH4 reactant gases, the Si0.82Ge0.18 layer is dep...An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is developed and the details of its construction and operation are reported. Using high purity SiH4 and GeH4 reactant gases, the Si0.82Ge0.18 layer is deposited at 550℃. With the measurements by double crystal X-ray diffraction (DCXRD), transmission electron microscopy (TEM) and Rutherford backscattering spectroscppy (RBS) techniques, it is shown that the crystalline quality of the SiGe layer is good, and the underlying SiGe/Si heterointerface is sharply defined.展开更多
Diffusion layers produced on carbon steel surface in vacuum titanizing process were investigated. Studies of layers thickness, their morphology, titanium, carbon and iron concentration depth profiles in the diffusion ...Diffusion layers produced on carbon steel surface in vacuum titanizing process were investigated. Studies of layers thickness, their morphology, titanium, carbon and iron concentration depth profiles in the diffusion zone of titanized layers were carried out. The effect of process parameters such as time and temperature on the kinetics of layer growth on steel surface was investigated. Tribocorrosion resistance of titanized layers was determined.展开更多
In this work, the deposition process features of a copper coating on stainless steel substrate, using the pulse vacuum arc spraying method were researched. A continuous layer of copper was deposited on a stainless ste...In this work, the deposition process features of a copper coating on stainless steel substrate, using the pulse vacuum arc spraying method were researched. A continuous layer of copper was deposited on a stainless steel substrate, and a high degree of coating adhesion to the substrate was demonstrated. The thickness of coating using application time was calculated, and the surface unevenness was estimated. Inside the coating layer substrate material elements were observed, that could appear as a result of simultaneously plasma spraying on the surface of the substrate. The feature of this method was discovered, that surface plasma plays a significant role in the deposition process. Finally, it was shown that the device with a pulsed arc could effectively be used in industry, since it is possible to change the layer thickness in the range of hundreds of microns by varying the deposition time.展开更多
The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as...The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni （Cr） solid solution,Ni （Si） solid solution and Ni （Fe） solid solution.The transition layer was composed of Ni （Cr） solid solution,Ni （Fe） solid solution,Ni （Si） solid solution,Fe （Ni） solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000.展开更多
文摘An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is developed and the details of its construction and operation are reported. Using high purity SiH4 and GeH4 reactant gases, the Si0.82Ge0.18 layer is deposited at 550℃. With the measurements by double crystal X-ray diffraction (DCXRD), transmission electron microscopy (TEM) and Rutherford backscattering spectroscppy (RBS) techniques, it is shown that the crystalline quality of the SiGe layer is good, and the underlying SiGe/Si heterointerface is sharply defined.
文摘Diffusion layers produced on carbon steel surface in vacuum titanizing process were investigated. Studies of layers thickness, their morphology, titanium, carbon and iron concentration depth profiles in the diffusion zone of titanized layers were carried out. The effect of process parameters such as time and temperature on the kinetics of layer growth on steel surface was investigated. Tribocorrosion resistance of titanized layers was determined.
文摘In this work, the deposition process features of a copper coating on stainless steel substrate, using the pulse vacuum arc spraying method were researched. A continuous layer of copper was deposited on a stainless steel substrate, and a high degree of coating adhesion to the substrate was demonstrated. The thickness of coating using application time was calculated, and the surface unevenness was estimated. Inside the coating layer substrate material elements were observed, that could appear as a result of simultaneously plasma spraying on the surface of the substrate. The feature of this method was discovered, that surface plasma plays a significant role in the deposition process. Finally, it was shown that the device with a pulsed arc could effectively be used in industry, since it is possible to change the layer thickness in the range of hundreds of microns by varying the deposition time.
基金Funded by"Xi-Bu-Zhi-Guang" Foundation of Chinese Academy of Sciences(No.XBZG-2007-5)Gansu Natural Science Foundation of China(No.0806RJYA004)Outstanding Youngth of Lanzhou University of Technology (No.Q200910)
文摘The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni （Cr） solid solution,Ni （Si） solid solution and Ni （Fe） solid solution.The transition layer was composed of Ni （Cr） solid solution,Ni （Fe） solid solution,Ni （Si） solid solution,Fe （Ni） solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000.
