Volume 0,Issue 10,2003 Table of Contents
2003(10):773-776.
Abstract:
An important experiment was reported in Nature by Oliver G. Schmidt and Karl Eberl: nanotubes can be formed from thin solid films of almost any material at almost any position, once these films are released from their substrate. This result can be expounded on the ground of the Thomas-Fermi- Dirac-Cheng (TFDC) electron theory.
An important experiment was reported in Nature by Oliver G. Schmidt and Karl Eberl: nanotubes can be formed from thin solid films of almost any material at almost any position, once these films are released from their substrate. This result can be expounded on the ground of the Thomas-Fermi- Dirac-Cheng (TFDC) electron theory.
2003(10):777-782.
Abstract:
采用真空电弧熔炼法制得式为Ni46Ti44Ta10(at％)的锭子，经过均匀化处理后，轧制成板材用作试样；采用DSC，XRD，SEM以及显微硬度测试等试验手段，对经时效处理的新型Ni-Ti-Ta形状记忆合金的性能进行了研究。结果表明：在300℃—550℃对Ni466Ti44Ta10合金进行时效处理后，有Ti11Ni14沉淀相析出，并且产生沉淀硬化效应；合金的相变温度和硬化程度随着时效处理的参数的不同而不同；经适当的时效处理，该合金不仅具有优越的形状记忆效应，而且可以达到最好的硬化效果。
采用真空电弧熔炼法制得式为Ni46Ti44Ta10(at％)的锭子，经过均匀化处理后，轧制成板材用作试样；采用DSC，XRD，SEM以及显微硬度测试等试验手段，对经时效处理的新型Ni-Ti-Ta形状记忆合金的性能进行了研究。结果表明：在300℃—550℃对Ni466Ti44Ta10合金进行时效处理后，有Ti11Ni14沉淀相析出，并且产生沉淀硬化效应；合金的相变温度和硬化程度随着时效处理的参数的不同而不同；经适当的时效处理，该合金不仅具有优越的形状记忆效应，而且可以达到最好的硬化效果。
3 Study of Ni-Cr High Temperature Solid Self-lubricating Materials Added with Ni Coated MoS2 Powders
2003(10):783-786.
Abstract:
通过硝酸镍分解-氢还原法制取镍涂覆二硫化钼粉末，加入到Ni-Cr基体合金中，以防止二硫化钼在高温制备过程及高温使用过程中的氧化分解。添加Ni包覆MoS2粉末，Ni-Cr25(w％)高温固体白润滑材料的机械性能优于未包覆材料，对(MoS2／Ni)20w％的高温固体白润滑材料的摩擦磨损性能分析表明：在室温和600℃下，材料有较低的摩擦系数。室温磨损率也很低，在高温下与未添加包覆材料相比前者具有很好的宽温带摩擦学性能。
通过硝酸镍分解-氢还原法制取镍涂覆二硫化钼粉末，加入到Ni-Cr基体合金中，以防止二硫化钼在高温制备过程及高温使用过程中的氧化分解。添加Ni包覆MoS2粉末，Ni-Cr25(w％)高温固体白润滑材料的机械性能优于未包覆材料，对(MoS2／Ni)20w％的高温固体白润滑材料的摩擦磨损性能分析表明：在室温和600℃下，材料有较低的摩擦系数。室温磨损率也很低，在高温下与未添加包覆材料相比前者具有很好的宽温带摩擦学性能。
2003(10):787-791.
Abstract:
研究了溶质原子浓度、Si晶体第二相、残余形变、外加莫来石(Mullite)短纤维及其交互作用，对二元Al—Cu合金时效析出行为的影响。试验材料采用挤压铸造方法制备，复合材料中纤维体积分数为18％。实验结果表明：随溶质原子浓度的升高，A1-Cu二元合金中GP，θ″和θ′相的析出都得到了相应加快；Si含量超过一定值后，随Si含量增加，A1-Cu-Si合金中GP区形成受到抑制，而θ″和θ′相的析出得到加快；形变对GP区的抑制和对θ″，θ′和θ相的加速析出具有十分明显的作用；纤维本身除对GP区抑制和对θ″，θ′相的析出加速外，还会与溶质原子、合金元素或第二相以及残余形变交互作用，使GP区被抑制，而θ″，θ′甚至θ相被加速析出等现象进一步加强。用位错理论能较好地解释析出反应延缓与加速的微观机理。
研究了溶质原子浓度、Si晶体第二相、残余形变、外加莫来石(Mullite)短纤维及其交互作用，对二元Al—Cu合金时效析出行为的影响。试验材料采用挤压铸造方法制备，复合材料中纤维体积分数为18％。实验结果表明：随溶质原子浓度的升高，A1-Cu二元合金中GP，θ″和θ′相的析出都得到了相应加快；Si含量超过一定值后，随Si含量增加，A1-Cu-Si合金中GP区形成受到抑制，而θ″和θ′相的析出得到加快；形变对GP区的抑制和对θ″，θ′和θ相的加速析出具有十分明显的作用；纤维本身除对GP区抑制和对θ″，θ′相的析出加速外，还会与溶质原子、合金元素或第二相以及残余形变交互作用，使GP区被抑制，而θ″，θ′甚至θ相被加速析出等现象进一步加强。用位错理论能较好地解释析出反应延缓与加速的微观机理。
2003(10):792-795.
Abstract:
An advanced method of producing AlN-Al3Ti/ZL101 in-situ composite is described in this paper. The microstructure of the in-situ composite is studied by the analyzing method of OM, SEM and TEM and the mechanical properties of the composite are also tested. The results show that the size of reinforcing phase Al3Ti in the composite is about 0. 5 u,m, which is distributed a-Al matrix uniformly. The size of reinforcing phase A1N is about 30 nm, which distribute inside of eutectic Si. The phase of Al3Ti has the same orientation relationship with a-Al and the phase of A1N has the same orientation relationship with eutectic Si. The tensile strength of AlN-Al3Ti/ZL101 in-situ composite is 369 MPa and it is higher than that of ZL101 matrix.
An advanced method of producing AlN-Al3Ti/ZL101 in-situ composite is described in this paper. The microstructure of the in-situ composite is studied by the analyzing method of OM, SEM and TEM and the mechanical properties of the composite are also tested. The results show that the size of reinforcing phase Al3Ti in the composite is about 0. 5 u,m, which is distributed a-Al matrix uniformly. The size of reinforcing phase A1N is about 30 nm, which distribute inside of eutectic Si. The phase of Al3Ti has the same orientation relationship with a-Al and the phase of A1N has the same orientation relationship with eutectic Si. The tensile strength of AlN-Al3Ti/ZL101 in-situ composite is 369 MPa and it is higher than that of ZL101 matrix.
2003(10):796-798.
Abstract:
采用化学气相沉积(CVD)技术制备了Ir／Re涂层复合材料，并在高温高真空条件下对复合材料进行扩散热处理。应用电子扫描波谱法探针研究了Ir／Re复合材料界面Re元素在Ir涂层中的扩散规律。应用半无限大扩散模型进行处理，得到了1400℃-2000℃温度范围的实验扩散系数，扩散系数与温度之间符合Arrhenius方程。根据实验结果推算，Ir／Re复合材料在2200℃时的工作寿命为47．6h。
采用化学气相沉积(CVD)技术制备了Ir／Re涂层复合材料，并在高温高真空条件下对复合材料进行扩散热处理。应用电子扫描波谱法探针研究了Ir／Re复合材料界面Re元素在Ir涂层中的扩散规律。应用半无限大扩散模型进行处理，得到了1400℃-2000℃温度范围的实验扩散系数，扩散系数与温度之间符合Arrhenius方程。根据实验结果推算，Ir／Re复合材料在2200℃时的工作寿命为47．6h。
2003(10):799-802.
Abstract:
A microstructure photograph was obtained when laser beam was turned off suddenly during laser cladding to synthesize TiC,,/Al composite. Based on the developed 3-D transient temperature field and fluid flow field simulation program for laser remelting, cladding reaetion features were considered and trial-and-error method was employed to choose every in-situ reaction temperature. According to the temperatures, the reaction enthalpies were added into temperature field calculation. Comparing the simulated temperature with the position lines of the different microstructure zones of the laser sudden stop test, the in-situ reaction temperatures under laser condition could be assessed. Some different parameters of processing were selected for the tests and numerical calculation. Through the agreement between the interface microstructure of the substrate and the cladding layer with the simulated temperature lines, the reliability of the assessed temperatures were proved validly. The assessed temperatures under laser condition could provide a reference for choosing the reasonable processing parameters and the optimized scheme.
A microstructure photograph was obtained when laser beam was turned off suddenly during laser cladding to synthesize TiC,,/Al composite. Based on the developed 3-D transient temperature field and fluid flow field simulation program for laser remelting, cladding reaetion features were considered and trial-and-error method was employed to choose every in-situ reaction temperature. According to the temperatures, the reaction enthalpies were added into temperature field calculation. Comparing the simulated temperature with the position lines of the different microstructure zones of the laser sudden stop test, the in-situ reaction temperatures under laser condition could be assessed. Some different parameters of processing were selected for the tests and numerical calculation. Through the agreement between the interface microstructure of the substrate and the cladding layer with the simulated temperature lines, the reliability of the assessed temperatures were proved validly. The assessed temperatures under laser condition could provide a reference for choosing the reasonable processing parameters and the optimized scheme.
2003(10):807-809.
Abstract:
分别熔炼了含Li和不含Li的2种7XXX系合金，合金经过双级时效(120℃ 160℃)后，利用TEM研究了第二级时效峰值状态时的微观组织。结果表明，2种合金的沉淀强化相均是η′(MgZn2)。与不含Li合金相比，含Li合金具有更细小的析出强化相和更窄的沉淀无析出带(PFZs)。
分别熔炼了含Li和不含Li的2种7XXX系合金，合金经过双级时效(120℃ 160℃)后，利用TEM研究了第二级时效峰值状态时的微观组织。结果表明，2种合金的沉淀强化相均是η′(MgZn2)。与不含Li合金相比，含Li合金具有更细小的析出强化相和更窄的沉淀无析出带(PFZs)。
2003(10):810-813.
Abstract:
采用真空自耗电弧炉熔炼制备Ti9Al合金，通过渗氢处理显著提高氢含量，在凸轮塑性试验机ЧПИ-2上以10mm／min的速度进行热模拟试验。研究发现：氢可以降低Ti9Al合金的相变温度，扩大α β区的温度范围；氢作为卢稳定剂会妨碍或完全抑制以Ti3Al为基的α2相的析出；钛合金的氢合金化可促使卢相在更低温度下稳定化，明显地提高了Ti9Al合金塑性。
采用真空自耗电弧炉熔炼制备Ti9Al合金，通过渗氢处理显著提高氢含量，在凸轮塑性试验机ЧПИ-2上以10mm／min的速度进行热模拟试验。研究发现：氢可以降低Ti9Al合金的相变温度，扩大α β区的温度范围；氢作为卢稳定剂会妨碍或完全抑制以Ti3Al为基的α2相的析出；钛合金的氢合金化可促使卢相在更低温度下稳定化，明显地提高了Ti9Al合金塑性。
2003(10):814-817.
Abstract:
利用极化曲线方法、电化学阻抗技术和扫描电子显微镜研究了非晶合金Zr55Al10Cu30Ni5在NaOH溶液中的腐蚀行为。极化曲线测试表明，非晶合金Zr55Al10Cu30Ni5在NaOH溶液中具有很好的耐蚀性能，阴极过程由电化学反应所控制，而阳极过程表现出钝化特征，在所研究的浓度范围内，钝化电流密度非常低，为1μA／cm^2～2μA／cm^2。电化学阻抗测试表明，电荷转移电阻随浓度的增大而增大，而后又有所降低。在阴极极化、开路电位和钝化电位下，非晶合金的Nyquist图由单容抗弧构成，具有很高的电荷转移电阻，表现出优良的耐蚀性。SEM和EDAX表明非晶合金在NaOH溶液中腐蚀轻微，各合金元素的溶解程度不同，腐蚀后表面出现了少量的氧元素。
利用极化曲线方法、电化学阻抗技术和扫描电子显微镜研究了非晶合金Zr55Al10Cu30Ni5在NaOH溶液中的腐蚀行为。极化曲线测试表明，非晶合金Zr55Al10Cu30Ni5在NaOH溶液中具有很好的耐蚀性能，阴极过程由电化学反应所控制，而阳极过程表现出钝化特征，在所研究的浓度范围内，钝化电流密度非常低，为1μA／cm^2～2μA／cm^2。电化学阻抗测试表明，电荷转移电阻随浓度的增大而增大，而后又有所降低。在阴极极化、开路电位和钝化电位下，非晶合金的Nyquist图由单容抗弧构成，具有很高的电荷转移电阻，表现出优良的耐蚀性。SEM和EDAX表明非晶合金在NaOH溶液中腐蚀轻微，各合金元素的溶解程度不同，腐蚀后表面出现了少量的氧元素。
2003(10):818-821.
Abstract:
The effect of neodymium on the silver nanoparticles prepared by vacuum deposition has been studied by TEM, EDX, HEED and XRD. Experimental results show that the size of silver particle decreases, its XRD peak disappears, and the component related to neodymium is amorphous due to the adding of neodymium. It is considered that the neodymium adding can increase the activation energy for surface diffusion to be 0. 071 eV, and the adsorption energy to be 0. 142 eV - 0. 426 eV based on the theory of Lewis-Campbell.
The effect of neodymium on the silver nanoparticles prepared by vacuum deposition has been studied by TEM, EDX, HEED and XRD. Experimental results show that the size of silver particle decreases, its XRD peak disappears, and the component related to neodymium is amorphous due to the adding of neodymium. It is considered that the neodymium adding can increase the activation energy for surface diffusion to be 0. 071 eV, and the adsorption energy to be 0. 142 eV - 0. 426 eV based on the theory of Lewis-Campbell.
2003(10):822-824.
Abstract:
The biocompatibility of two dental casting alloys of Au-Ag-Pd-Cu was investigated by MTT assay. The cells morphology was observed with a phase-contrast microscope. In the experiment, the L-929 cell line and RPMI1640 with 5% FBS were used. The results show that the cell morphology is good, and the growth of cells is vigorous after the cells have been cultured and steeped in the two alloys for 3 days and 5 days. The cytotoxicity of two alloys was ranked as 0 ~ 1 with a good biocompatibility.
The biocompatibility of two dental casting alloys of Au-Ag-Pd-Cu was investigated by MTT assay. The cells morphology was observed with a phase-contrast microscope. In the experiment, the L-929 cell line and RPMI1640 with 5% FBS were used. The results show that the cell morphology is good, and the growth of cells is vigorous after the cells have been cultured and steeped in the two alloys for 3 days and 5 days. The cytotoxicity of two alloys was ranked as 0 ~ 1 with a good biocompatibility.
2003(10):829-831.
Abstract:
The nanocrystalline powder of Ti4+ doped with SnO2 was prepared by the sol-gel method, and its electric conductivity and wet a-bility with silver were improved by doping and chemical platting. The results show that the uniformity, contact resistance and machinability of the Ag/SnO2 electric contact material were improved by using this technology.
The nanocrystalline powder of Ti4+ doped with SnO2 was prepared by the sol-gel method, and its electric conductivity and wet a-bility with silver were improved by doping and chemical platting. The results show that the uniformity, contact resistance and machinability of the Ag/SnO2 electric contact material were improved by using this technology.
Shao Huiming
,
Zhou Lian
,
Zhang Pingxiang
,
Feng Yong
,
Duan Zhenzhong Zheng Huiling''''
,
Tang Xiaodong
,
Li Chengshan
,
Zhang Xiaocong
,
Sun Xiangyun
2003(10):832-835.
Abstract:
The influence of initial packing density on the superconducting properties of Bi-2223/Ag tape has been studied. The results indicate that the processing of cold-isostatic-pressing(CIP) can increase the fill factor and the ]r of tape. The number of bubble after first heat treatment is reduced by CIP processing which can improve the uniformity of Jr along the longitudinal direction to be more suitable for the fabrication of long Bi-2223/Ag tapes. During rolling, the CIP tape is more wider than the loose packed tape. With more fraction of Bi-2223 phase, dense core and less porosity, the Jc of the CIP tapes is increased.
The influence of initial packing density on the superconducting properties of Bi-2223/Ag tape has been studied. The results indicate that the processing of cold-isostatic-pressing(CIP) can increase the fill factor and the ]r of tape. The number of bubble after first heat treatment is reduced by CIP processing which can improve the uniformity of Jr along the longitudinal direction to be more suitable for the fabrication of long Bi-2223/Ag tapes. During rolling, the CIP tape is more wider than the loose packed tape. With more fraction of Bi-2223 phase, dense core and less porosity, the Jc of the CIP tapes is increased.
15 Aging Treatment and Magnetic Properties for the 2:17 Type SmCo Permanent Magnets of High Coercivity
2003(10):836-839.
Abstract:
By using X-ray diffraction, scan electron microscope, X-ray electron energy analysis and magnetic measurement, the relationship between magnetic properties and microstructure for the high intrinsic coercivity 2:17 SmCo permanent magnets during aging treatment were investigated. It is found that the alloy decomposed into a 2 : 17 phase and a 1: 5 phase as soon as the aging treatment started, and the precipitates at grain boundaries have an effect on the enhancement of coercivity. The variation of intrinsic coercivity at different aging processes can be considered as the variation of the domain wall energy difference between the two phases.
By using X-ray diffraction, scan electron microscope, X-ray electron energy analysis and magnetic measurement, the relationship between magnetic properties and microstructure for the high intrinsic coercivity 2:17 SmCo permanent magnets during aging treatment were investigated. It is found that the alloy decomposed into a 2 : 17 phase and a 1: 5 phase as soon as the aging treatment started, and the precipitates at grain boundaries have an effect on the enhancement of coercivity. The variation of intrinsic coercivity at different aging processes can be considered as the variation of the domain wall energy difference between the two phases.
2003(10):840-843.
Abstract:
TiC reinforced FeAl intermetallic matrix composite coatings were fabricated on the substrate of 1Crl8Ni9Ti by laser cladding, the dry sliding wear resistance of the composite coating was evaluated under dry sliding wear conditions as functions of applied load and sliding speed. The wear mechanisms were discussed based on the worn surfaces and wear debris examinations. Results showed that the laser clad TiC/FeAl intermetallic matrix composite coatings have outerstanding wear resistance under the dry sliding wear test conditions. The wear rate of TiC/FeAl composite coatings increases with increasing applied load and sliding speed. SEM observation of worn surfaces and wear debris indicated that there is a transition of wear mechanism from abrasive wear to adhesive wear with increasing applied load. Furthermore, with the increase of volume fraction of TiC carbide in laser clad coating, the resistance to abrasive wear is improved, and the adhesion between test specimen and counter-face material is reduced, leading to an excellent abrasive and adhesive wear resistance.
TiC reinforced FeAl intermetallic matrix composite coatings were fabricated on the substrate of 1Crl8Ni9Ti by laser cladding, the dry sliding wear resistance of the composite coating was evaluated under dry sliding wear conditions as functions of applied load and sliding speed. The wear mechanisms were discussed based on the worn surfaces and wear debris examinations. Results showed that the laser clad TiC/FeAl intermetallic matrix composite coatings have outerstanding wear resistance under the dry sliding wear test conditions. The wear rate of TiC/FeAl composite coatings increases with increasing applied load and sliding speed. SEM observation of worn surfaces and wear debris indicated that there is a transition of wear mechanism from abrasive wear to adhesive wear with increasing applied load. Furthermore, with the increase of volume fraction of TiC carbide in laser clad coating, the resistance to abrasive wear is improved, and the adhesion between test specimen and counter-face material is reduced, leading to an excellent abrasive and adhesive wear resistance.
2003(10):844-847.
Abstract:
A new kind of NdFeB magnet was produced by spark plasma sintering technique. Magnetic properties, microstructure and constituents were investigated by means of B-H loop-line instrument, scanning electron microscope and energy dispersive X-ray detector. The effects of processing conditions on the magnetic properties, dimensional precision as well as density were studied. The electrochemical property in electrolytes and the corrosion behavior in oxidation environment were examined for the magnets. It is found that the microstructure of SPS NdFeB magnet is different from that of conventional one, the grain size is fine and uniform while the distribution of the Nd-rich phase is heterogeneous. The optimal magnetic properties of the SPS NdFeB magnets obtained so far are of a maximum energy product of 240 kJ / m3 and a coercive force of 1 260 kA/m. The density of the magnet reaches 7. 58 g/cm3 as well as the dimensional precision of the magnets is about 20 p.m. Meanwhile, the electrochemical property and the corrosion resistance of SPS NdFeB magnets are much better if compared with conventional one.
A new kind of NdFeB magnet was produced by spark plasma sintering technique. Magnetic properties, microstructure and constituents were investigated by means of B-H loop-line instrument, scanning electron microscope and energy dispersive X-ray detector. The effects of processing conditions on the magnetic properties, dimensional precision as well as density were studied. The electrochemical property in electrolytes and the corrosion behavior in oxidation environment were examined for the magnets. It is found that the microstructure of SPS NdFeB magnet is different from that of conventional one, the grain size is fine and uniform while the distribution of the Nd-rich phase is heterogeneous. The optimal magnetic properties of the SPS NdFeB magnets obtained so far are of a maximum energy product of 240 kJ / m3 and a coercive force of 1 260 kA/m. The density of the magnet reaches 7. 58 g/cm3 as well as the dimensional precision of the magnets is about 20 p.m. Meanwhile, the electrochemical property and the corrosion resistance of SPS NdFeB magnets are much better if compared with conventional one.
2003(10):848-851.
Abstract:
Mo2Ni3Si/NiSi wear-resistant metal silicide composite coatings were fabricated by laser cladding with 39Mo-35Ni-26Si(wt% ) powder as precursor on the substrate of austenitic stainless steel 1Crl8Ni9Ti. The Mo2Ni3Si/NiSi composite coatings have a fine microstructure consisting of MojNisSi primary metal silicide dendrites and the interdendritic Mo2Ni3Si/NiSi eutectic structure. The dry sliding wear test indicates that the slight preferential wear of the Mo2Ni3Si/NiSi eutectic structure occurs during the dry sliding wear process, resulting in the slight protrusion of Mo2Ni3Si metal silicide reinforced phase. Due to the high hardness and strong covalent atomic bonding of Mo2Ni3Si metal silicide, no deformation and adhesion transfer were observed on the worn surface. Laser clad Mo2Ni3Si/NiSi metal silicide composite coating has an excellent wear resistance under the dry sliding wear test condition. Wear resistance of the composite coating is up to 56 times higher than that of the austenitic stainless steel 1Crl8Ni9Ti.
Mo2Ni3Si/NiSi wear-resistant metal silicide composite coatings were fabricated by laser cladding with 39Mo-35Ni-26Si(wt% ) powder as precursor on the substrate of austenitic stainless steel 1Crl8Ni9Ti. The Mo2Ni3Si/NiSi composite coatings have a fine microstructure consisting of MojNisSi primary metal silicide dendrites and the interdendritic Mo2Ni3Si/NiSi eutectic structure. The dry sliding wear test indicates that the slight preferential wear of the Mo2Ni3Si/NiSi eutectic structure occurs during the dry sliding wear process, resulting in the slight protrusion of Mo2Ni3Si metal silicide reinforced phase. Due to the high hardness and strong covalent atomic bonding of Mo2Ni3Si metal silicide, no deformation and adhesion transfer were observed on the worn surface. Laser clad Mo2Ni3Si/NiSi metal silicide composite coating has an excellent wear resistance under the dry sliding wear test condition. Wear resistance of the composite coating is up to 56 times higher than that of the austenitic stainless steel 1Crl8Ni9Ti.
2003(10):852-854.
Abstract:
Zirconia powder was prepared by a high-temperature-aging method. It is found from experiment results that the prepared zirconia powder has high surface area and high thermal stability. It is an important reason for preparing zirconia powder with high surface area and high thermal stability, mainly due to the marked decreases of amorphous zirconia energy by high-temperature-aging, then the increase of its crystallization temperature and thermal stability.
Zirconia powder was prepared by a high-temperature-aging method. It is found from experiment results that the prepared zirconia powder has high surface area and high thermal stability. It is an important reason for preparing zirconia powder with high surface area and high thermal stability, mainly due to the marked decreases of amorphous zirconia energy by high-temperature-aging, then the increase of its crystallization temperature and thermal stability.
2003(10):855-858.
Abstract:
A novel vacuum melting method, which was characterized by the application of brazing foil, was proposed. With BNi-2 nickel-based brazing foil, a pre-placed CoCrW adhesive coating was melted in a vacuum furnace. The microstructure and fretting wear resistance of the coating were studied. The results showed that fully dense coating was obtained. A good metallurgical bonding was achieved not only between coating and substrate but also hard phases and bonding phases. The microstructure of the coating was composed of hard phases such as Co6W6C, Cr7C3, W2C, Ni3B, CrB and ductile phases including nickel-based and cobalt-based solid solutions. Based on the dense microstructure, the excellent metallurgical bonding and the hard phases strengthening, it is found that the fretting wear resistance of vacuum melting CoCrW coating was remarkably superior to the plasma spraying CoCrW coating and 1Crl8Ni9Ti stainless steel.
A novel vacuum melting method, which was characterized by the application of brazing foil, was proposed. With BNi-2 nickel-based brazing foil, a pre-placed CoCrW adhesive coating was melted in a vacuum furnace. The microstructure and fretting wear resistance of the coating were studied. The results showed that fully dense coating was obtained. A good metallurgical bonding was achieved not only between coating and substrate but also hard phases and bonding phases. The microstructure of the coating was composed of hard phases such as Co6W6C, Cr7C3, W2C, Ni3B, CrB and ductile phases including nickel-based and cobalt-based solid solutions. Based on the dense microstructure, the excellent metallurgical bonding and the hard phases strengthening, it is found that the fretting wear resistance of vacuum melting CoCrW coating was remarkably superior to the plasma spraying CoCrW coating and 1Crl8Ni9Ti stainless steel.
2003(10):859-861.
Abstract:
Barium strontium titanate (BST) ceramic film is prepared on titanium substrate by micro-plasma oxidation. It is discussed that the influence of Ba/Sr molar ratio on ceramic film composition. The composition, morphology and element distribution of ceramic film are analyzed. It is indicated that the BST ceramic film with relatively smooth surface and homogeneous element composition can be formed in the condition of selected processing parameters.
Barium strontium titanate (BST) ceramic film is prepared on titanium substrate by micro-plasma oxidation. It is discussed that the influence of Ba/Sr molar ratio on ceramic film composition. The composition, morphology and element distribution of ceramic film are analyzed. It is indicated that the BST ceramic film with relatively smooth surface and homogeneous element composition can be formed in the condition of selected processing parameters.
2003(10):862-865.
Abstract:
用微液相合成法制备了PbHPO_3超细粉末。得到的产物经粉末X射线衍射(XRD)和透射电镜(TEM)检测表明为纯净的PbHPO_3和2PbO·PbHPO_3·0.5H_2O。PbHPO_3粒子为均匀球形,尺度范围30nm～60nm,2PbO·PbHPO_3·0.5H_2O粒子为棒状,尺度范围(20～40)nm×(50～200)nm。
用微液相合成法制备了PbHPO_3超细粉末。得到的产物经粉末X射线衍射(XRD)和透射电镜(TEM)检测表明为纯净的PbHPO_3和2PbO·PbHPO_3·0.5H_2O。PbHPO_3粒子为均匀球形,尺度范围30nm～60nm,2PbO·PbHPO_3·0.5H_2O粒子为棒状,尺度范围(20～40)nm×(50～200)nm。
2003(10):866-868.
Abstract:
利用试样在悬浮状态时重力与悬浮力相等，从而得到悬浮感应器的高频电流，进而得到悬浮感应器输入试样的功率。利用悬浮试样在热平衡状态输入功率与能量耗散平衡，从而得到合金的高温热辐射系数。并且利用这种方法测得(TbDy)Fe2合金在T=1455℃的热辐射系数为0．524。
利用试样在悬浮状态时重力与悬浮力相等，从而得到悬浮感应器的高频电流，进而得到悬浮感应器输入试样的功率。利用悬浮试样在热平衡状态输入功率与能量耗散平衡，从而得到合金的高温热辐射系数。并且利用这种方法测得(TbDy)Fe2合金在T=1455℃的热辐射系数为0．524。
