ZHANG Shao-qing, CUI Yan, SONG Ying-gang. Microstructural Study of SiCp/Al Composite Prepared by Pressureless Infiltration[J]. Journal of Materials Engineering, 2000, 0(10): 3-6.
The microstructure of SiCp/Al composite made by pressureless infiltration was studied by means of XRD,ZEM,OM and TEM. The results of investigation show that the SiC,Al,MgAl2O4,Si,and Mg2Si phases exist in the materials. There are no coarse eutectic platelets in the structure,and the SiC particulates existing in the matrix of aluminium alloy make the latter to be a continuous space network. The Si and Mg2Si phases precipitate in the matrix. The high resolution transmission electron microscopy shows that the MgAl2O4 phase exists at the interface between SiC ans matrix and the Al4C3 phase is not found in the interfacial region.
QIAO Liang, ZHOU He-ping, LIU Yao-cheng, WANG Yu-di. Migration of Liquid Phases in Low-temperature Sintering of AlN[J]. Journal of Materials Engineering, 2000, 0(10): 7-10.
SEM/EDAX and XRF were used to study the migration of liquid phases in the low temperature sintering of AlN with (YCa)F3 as additive. Y and Ca were considered as tracer element, which indicated the distribution of liquid phases during the sintering. The results show that the liquid phases, drived by the densification of green bodies and the growth of grains, can be migrated towards the surface of the specimen.
LIU Dao-xin, TANG Bin, PAN Jun-de, HE Jia-wen. Investigation on Glow-discharge Ionized Nickel-chromizing with Arc Source of Ti Alloy and Its Properties[J]. Journal of Materials Engineering, 2000, 0(10): 11-14.
A new technique of glow-discharge ionized surface alloying with arc source was used to treat Ti5Al2.5Sn alloy. The microstructure and constituent distribution in diffusion layer were studied. The wear resistance and the galvanic corrosion susceptibility of the alloyed surface layer contacted with titanium alloy Ti5Al2.5Sn were evaluated. It is found that a composite modified surface of NiCr coating over nickel-chromium diffusion layer can be quickly formed with the new technology. The alloyed surface consists of Ni3Ti, Ni3Al, Cr2Ti and other phases. The hardness and the wear resistance of the alloyed surface are higher than that of nitrided surface. The modified titanium alloy has high corrosion resistance in Cl-1 environment and low galvanic corrosion susceptibility contacted with Ti base metal.
SONG Jian-quan, LIU Zheng-tang, YU Zhong-qi, GENG Dong-sheng, ZHENG Xiu-lin. The Analysis of Specialities of GexC1-x Films Prepared by RF Magnetron Reactive Sputtering[J]. Journal of Materials Engineering, 2000, 0(10): 15-17,21.
A germanium carbide (GexC1-x) film was prepared by RF magnetron reactive sputtering at various mass flow ratios of methane to argon and methane [CH4/(CH4+Ar)] from a germanium target. The film thickness was measured by optical interferometer and its deposition rate was calculated according to thickness. The results show that not only the deposition rate is not decreased greatly after the target poisoned, but also the germanium atom ratio in GexC1-x film can be varied in great range All these are different from the common magnetron reactive sputtering. The reason why the GexC1-x film has these specialties is the behavior of reactive gas (CH4) particles after the target poisoned This conclusion is universal to deposit carbide by magnetron reactive sputtering.
ZHANG Zhen-qi, HONG Quan, YANG Guan-jun, LUO Guo-zhen. Research on Microstructure of Ti600 Alloy after Creep Test[J]. Journal of Materials Engineering, 2000, 0(10): 18-21.
Microstructure of a near αTi alloy Ti600,containing Y with nominal composition of Ti-6Al-2.8Sn-4Zr-0.5Mo-0.4Si-0.1Y (wt%), was researched A lot of experiments of creep was done OM and TEM observation were carried out. The results show that the precipitation α2 phase (Ti3Al) and silicides(Ti5Si3) are produced after different creep test. RE element Y play great role in this alloy Yttrium oxide would localize at the grain boundary and near the dislocation as the matrix and lattice is different, yttrium oxide particles is precipitated RE element Y addition can refine the as-cast microstructure, The average diameter of yttrium oxide (Y2O3) is no more than 0.6μm, the maximum diameter is less than 1μm.
ZHAN Mao-sheng, LI Jian-ping. Study of Polyimide/SiO2 Solid-state Alloy by the Mechanical Chemistry[J]. Journal of Materials Engineering, 2000, 0(10): 22-24,28.
Polyimide (PI)/SiO2 solid-state alloy was produced by mechanical alloying process according to the principle of mechanical chemistry, and the microstructure was observed by SEM, which shows that after 600h ball-milling the PI powders blend with ceramic powders homogeneously, and the ceramic powder cling to the side of PI powders. Then the study on the content of each elements in the alloy tells that there exists a critical time to get a mechanical alloy. As long as ball-milling time gets to 600h,the content of the blends is close to theoretical value, The samples were also analyzed by IR and DMA, and the result indicates that the strong interface between polymer and ceramic powders formed by chemical reaction in the mechanical process, which make the alloy a good thermomechanical properties.
TIAN Su-gui, ZHANG Lu-ting, WANG Gui-hua, QIAO Rui-qing, JIN Shou-ri, LI Tie-fan. Internal Oxidation of AlN Particles Reinforced Cu-Base Composites[J]. Journal of Materials Engineering, 2000, 0(10): 25-28.
Microstructures and properties of AlN particle reinforced Cu-base composites were compared before and after internal oxidation treatment. The results show that internal oxidation of the particles reinforced Cu-base composites may be achieved in the medium of high pure nitrogen gas. The internal oxides grow on the surfaces of AlN particles, and are distributed dispersive within composites matrix. The enhanced of compression resistance resulted from the role of the fine grain and particles dispersed strengthening. The densification and interfacial bonding strength of the composites can be improved by means of internal oxidation treatment, which is supposed to be one of the main reason for the wear resistance enhanced.
LIU Yu-yan, WAN Zhi-min, DU Xing-wen. Fatigue Behavior of Polyester/Rubber Composites and Rayon/Rubber Composites under Periodic Loading[J]. Journal of Materials Engineering, 2000, 0(10): 29-32.
By using a special fatigue testing system for cord/rubber composites, the fatigue damage accumulation characteristics of rubber composites under periodic loading were assessed, and the fatigue life prediction equations were given in the case of polyester/rubber composites and rayon/rubber composites. The effect of frequency on the fatigue life of rubber composites and the variation of surface temperature of rubber composites during fatigue process were also examined. The results indicate that high heat is followed with fatigue process of rubber composites. This is the main difference between rubber composites and brittle composites. The surface temperature canbe reached to 100℃ for polyester/rubber composites and 40℃ for rayon/rubber composites during fatigue experiments. The effect of frequency on the fatigue life of different rubber composites is different. The fatigue life of polyester/rubber composites with high viscoelasticity are increased when frequency is increased and the fatigue life of rayon/rubber composites with low viscoelasticity vary little when frequency ischanged.
LI Bin, ZHANG Xiao-yun, TANG Zhi-hui, SITU Zhen-min. Development of a Hard Film YTF-1 with Displacing Corrosion Preventive Properties for Aircraft[J]. Journal of Materials Engineering, 2000, 0(10): 33-35.
YTF-1 is a clear hard film with water displacing corrosion preventive properties for aircraft. YTF-1 contains resins,water displacing additives,organic corrosion inhibitors,gasoline solvents and alcohol accessory ingredients. It has advantages of water displacing properties and effective corrosion prevention for aircraft surface metals,such as steel,copper,aluminium,magnesium,zinc,cadmium. Its technical properties conform to the requirements of MIL-C-85054B(AS)《corrosion preventive compound,water displacing,clear(AMLGUARD)》.
LI Ning, LI De-yu, ZHAI Shu-fang, KURACHI Mitsuo, ZHOU De-rui. Preparation of Lead Alloy Anodes and their Anodic Properties[J]. Journal of Materials Engineering, 2000, 0(10): 36-39.
Some lead alloy anodes prepared by open air casting or by vacuum diffusion bonding and their electrolytic properties are studied using Pb-5%Sn, Pb 0.5%Ag, and Pb-1%In-0.5%Ag alloys, respectively. The Pb-5%Sn anode prepared by vacuum diffusion bonding method at 750℃ shows lower oxygen over-voltage (1.75V vs. SCE) than that of another anodes. After anodic oxidation, compact oxide layer with single α-PbO2 is observed on this surface, the other anodes have oxide layer with combined α-PbO2 and β-PbO2 or PbSO4. The rate of weight loss of this anode is less than that of the other Pb-5%Sn anodes prepared by open air casting method, the rate of weight loss of Pb-0.5%Ag and Pb-1%In-0.5%Ag anodes are less than Pb-5%Sn anodes. It is found that the Pb-5%Sn anode prepared by high temperature vacuum diffusion bonding method is preferable to use for high speed electrogalvanizing, because of low oxygen over voltage, low weight loss, and low lead pollution, comparatively.
Zhao, Jia-xiang. Development and Prospect of Advanced Composite Materials[J]. Journal of Materials Engineering, 2000, 0(10): 40-44,48.
In this paper the orientation of the development of advanced composite materials in 21 century is briefly summarized from the technical view point. They are low cost, high performance, multiple function as well as intellectualization.
BAI Shi-hong, QIAO Sheng-ru, SHU Wu-bing, KANG Mo-kuang. Testing and Characterization of Mechanical Properties for Advanced Ceramics at High Temperatures[J]. Journal of Materials Engineering, 2000, 0(10): 45-48.
Testing and characterization technology of properties for ceramics and CMC at high temperatures is briefly introduced,and the preliminary study on damaged mechanism and fracture model of ceramics at high temperatures are also made in this paper.
