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Abstract:Important Tungsten alloys include W Ni Fe, W Ni Cu, W Cu, and WC Co. In the 21th century, nanograin tungsten alloys will emerge as new materials with muctiple functions and ultrahigh properties. Nanograin bulk tungsten alloys prepared from nanocrystalline powders will exhibit superior physical and mechanical properties, and have potential advantages in microelectronic applications, such as, heat sinks, electronic packages, and anti armor applications. This paper reviews the current research on nanograin refractory tungsten alloy composite powders, introduces numerous technique for nanometer tungsten alloy powder preparation, and points out research directions of nanometer refractory tungsten alloy materials.

Abstract:The double shear specimen was designed for the study of the creep behavior of nickel base single crystal superalloys at high temperature. The creep stress and strain distributions and the influence of boundary conditions for the specimen are studied in the present paper. The results show that a preliminary analysis, by using the finite element code ABAQUS and RIGID SURFACE as a boundary condition for loading is conservative because a homogeneous state of shear stress is maintained only up to shear strains of the order of 10%. Using a more realistic boundary condition for loading (ABAQUS option: CONTACT PAIR), the homogeneous state of shear stress in the double shear specimen is maintained throughout creep up to much higher shear strains than that of the originally estimated. A macrorelationship has been built between the material creep properties (Norton law) and the macrobehavior of the double shear behavior, so that the material creep properties can be derived from the creep experiments of double shear specimens, and corresponding equations have been presented. Therefore, the further work on crystallographic anisotropic finite element creep stress analysis of our double shear creep specimen will be based on the more realistic loading condition which is represented by the ABAQUS option CONTACT PAIR A good agreement has been obtained between the creep behavior of the double shear damage specimen of the experiment and finite element analysis on nickel base single crystal superalloys.

Abstract:研究了Ti-40(Ti-25V-15Cr-0.2Si)阻燃鈦合金中的第二相及其對合金性能的影響。研究結(jié)果表明：固溶溫度升高，Ti40合金析出第二相的趨勢增大；低于850℃固溶，合金中沒有第二相析出，高于850℃固溶，合金中析出棒狀α相和少量Ti5Si3相；910℃固溶＋600℃時效，合金存在第二相有α和Ti5Si3相；860℃固溶＋600℃時效，合金僅存在Ti5Si3相，固溶時效態(tài)存在的第二相對合金的性能沒有明顯影響，540℃，100h熱暴露，合金中存在的各種形態(tài)的α相和Ti5Si3析出物，明顯降低合金的熱穩(wěn)定性能。

Abstract:Using one frequency field to inductively heat the solid metal and another frequency field to confine the molten metal to a near net shape without contacting with the mold, a dual frequency eletromagnetic shaping process of liquid metal has been successfully realized by high supersonic and two high frequency electromagnetic fields. Owing to the fact that induction heating and electromagnetic shaping for different frequency fields can be adjusted separately, the control of the high supersonic dual frequency electromagnetic shaping of liquid metal is easier not only than single frequency electromagnetic shaping, but also than dual high frequency electromagnetic shaping. By designing suitable induction heating and electromagnetic shaping coils, some near net shaped sample parts with elliptical and menisoid cross sections have been produced using high supersonic dual frequency electromagnetic shaping process.

Abstract:Metal matrix composite (MMC) surface layer have been formed on 6061 aluminium alloy surface by laser cladding of using a 2kW continuous wave (CW) Nd YAG laser. The TiC particle reinforced Al Ti composite coating was prepared by in situ contact reaction with preplaced powder mixtures of Ti and SiC. The formation mechanism of TiC particles has been studied. It was found that composite coating consisting of TiC particles dispersed in coating matrix could be obtained using the correct ratio of Ti to SiC powders and a laser power density. Compound material cladding coating mainly consists of Ti Al intermetallic compound and Al supersaturated solid solution. The coating was characterized by good metallurgical bonding between the coating and the substrate, good wettability between the reinforcement TiC and the coating matrix,and a fine grain structure. The results show that the composite coating greatly enhances the surface hardness.

Abstract:By the response curved surface technique (First, in line with actually chosen response curved surface regression and then in terms of the corresponding coefficient estimated by the least square method),it is possible to get the initial response curved surface regression equation. Based on the magnitude of the significance inspection value, the less significant variable of the coefficient can be eliminated by the lease square estimation ,the final curved surfac equation is established. In this paper, the response curved regression is chosen for making up for the deficiency of the orthogonal experiments in the research of the nanometer size TiO 2/UPR(Unsaturated Polyester Resins) composite. The results show that the response curved surface regression analysis technique is a good mathematics analysis method in the materials research.

Abstract:The influence of pH value on corrosion behavior of N ion implanted SUS316L stainless steel, Co Cr alloy, CPTi and Ti 6Al 4V alloy surgery medical materials has been investigated in Hank's solution using electrochemical technology. Experimental results indicate that corrosion potentials of specimens decline, and E b and crevice corrosion potentials of SUS316L stainless steel and Co Cr alloy also decline with decreasing pH value, which results in an increase of the sensibility of local corrosion. The corrosion rates of CPTi and Ti 6Al 4V alloy also increase in Hank's solution with much lower pH value.

Abstract:The microstructure, mechanical properties, the mechanisms of strengthening and toughening for the 10%C f/SiO 2 composite prepared by vacuum hot pressing, were studied. The SiO 2 glass matrix crystallized partially after hot pressing. The composite has a lamellar structure with the carbon fibers in parallel with the hot pressing plane. The bending strength, fracture toughness and fracture strain of the composite are significantly improved, compared with that of the matrix. Bridging and pulling out of carbon fibers and crabon fibers and crack deflection induced by the carbon fibers are the principal mechanisms of strengthening and toughening.

Abstract:Heteroepitaxial diamond films were grown on Si(100) via electron emission with a bias voltage, by using microwave plasma CVD and hot filament CVD. The piezoresistivity and magnetoresistivity of p type diamond films obtained by the cold implantation and rapid annealing have been investigated.The experimental results show that epitaxial diamond films have pronounced piezoresistivity and magnetoresistivity effect and can still be operated under extreme conditions such as high temperature, heavy radiation and a strong chemical corrosive environment

Abstract:Ti3Al基的Ti-24A1-14Nb-3V-0.5Mo(at%)合金為非理想的超塑材料.用超塑壓縮方法研究了合金的超塑變形行為,分析了變形量和應變速率對流變應力及組織演變的影響.結(jié)果表明所研究合金的最佳超塑變形溫度為980 ℃.在980 ℃,2×10-3s-1的條件下,應變速率敏感性指數(shù)值為0.55.應變速率對合金超塑壓縮時的力學行為和組織演變有顯著的影響.

Abstract:The microstructures of ZrC particle reinforced tungsten matrix composite (ZrC P/W, 30vol%ZrC particles) have been investigated using XRD, SEM and TEM. The experimental results indicate that the ZrC particles inhabit the growth of tungsten grains during sintering. The relative density of the composite is less than that of monolithic tungsten. W atoms diffuse in the lattice of ZrC, resulting in a formation of (Zr, W)C solid solution in ZrC particles, and a little of Zr diffuse in W lattice, resulting in a metallurgical bonding of ZrC particles to W matrix. W 2C and ZrO 2 phases were found rarely in the composites. At room temperature, the fracture toughness, elastic modulus and hardness of the composite increase because of the additive ZrC particles, but the flexural strength of the composite is lower than that of monolithic tungsten. The toughening mechanisms of ZrC P/W composite are crack deflection and grain refining.

Abstract:The effect of phase composition of tungsten oxide on the homogeneity of ultrafine tungsten powder has been studied using a conventional hydrogen reduction technique. The results show that ultrafine and homogeneous tungsten powder can be produced from single phase tungsten oxide. The tungsten powder made by multi phase oxides may be fine , but not homogenous due to differences between the reduction rates (or redution paths) of various oxides.

Abstract:針對稀土金屬釹熔鹽電解過程中存在的一系列問題 ,研制了一種新型的坩堝材料。該材料是以 Nd2 O3為基分別添加不同氧化物的陶瓷材料 ,它是通過粉末燒結(jié)法制備并進行了電解實驗。結(jié)果表明 :該材料有較好的耐蝕性 ,陶瓷材料的腐蝕率小于 2× 10 - 2 g/ cm2 .h。工業(yè)實驗條件下 ,材料的腐蝕率為 6 .5× 10 - 2 g/ cm2 .h

Abstract:A technology of Au thick film by ion plating have been worked out according to the investigation of the transition coating of Au thick film by ion plating. The technology consists of several steps including ionic cleaning of sample surface, plating of Ni Cu transition coating and heat treatment in the chamber etc. All steps can be realized by once charging. The results of test run show that number of reciprocating movement of the friction surfaces reached 120 times at the speed of 2.5 m/s, which meet requirement completely.

Abstract:The effects of strain and alloy composition on some important properties of 316L stainless steel fibre are discussed in this paper. The experimental results show that alloying element content influence the austenitic stability of stainless steel. The lower the element content, the poorer the austenitic stability. The main reason for adjusting the alloy content of stainless steel fibre is to inhibit unstable austenite transformation into martensite under strain.

Abstract:針對電動車用大型動力Ni/MH電池工作溫度較高的特點，系統(tǒng)地研究了3種工作溫度（25℃，40℃和60℃）對貯氫合金RENi3.55Mn0.4Co0.75Al0.3電化學性能的影響。研究結(jié)果表明，RENi3.55Mn0.4Co0.75Al0.3合金具有單一的CaCu5型LaNi5相結(jié)構，當工作溫度從25℃提高至60℃時，合金的放氫平衡壓力從0．04MPa升高至0．13MPa，同時放氫平臺的寬度變窄，傾斜度增大，從而導致該合金的放氫量降低；隨著溫度的升高，合金的活化性能得到顯著改善，但合金的最大放電容量和循環(huán)穩(wěn)定性明顯降低；而中高溫（40℃和60℃）時合金的高倍率放電性能則明顯優(yōu)于室溫（25℃）時的高倍率放電性能。

Abstract:The effect of current density on electroplating titanium in molten NaCl KCl was studied, and a comparison made of the different between the effects of direct current and pulse current in molten salt electroplating. The new technique of pulse current molten salt electroplating and its improvement of e the diffusion limited process was studied. A good Ti coating has been obtained on the surface of metal substrate.

Abstract:采用 H1Cr2 6 Ni2 1作為過渡層焊絲 ,焊接 Monel40 0 / 16 Mn R復合板。研究了復合板焊接接頭的彎曲性能、拉伸強度、主要化學元素在焊縫中的擴散程度及其微觀組織。結(jié)果表明 ,焊縫成形良好 ,在距復層焊縫表面 2 .4mm范圍內(nèi) ,焊絲化學成份對復層焊縫化學成份的稀釋率為 0。焊接接頭的拉伸強度為 6 30 MPa。面彎角大于等于 12 0°,背彎角為 180°,側(cè)彎角大于等于 10 0°。焊接接頭具有良好的綜合機械性能。

Abstract:A precious continuous casting technique and equipment suitable for the production of Ag and its alloys are discribed in this paper. The equipment possesses the advantages of precision, miniaturization, vacuum or gass protective melting and casting, especially suitable for producing the precious metals demanding high purity, containing easily volatile components and severely oxidized owing to gass absorption under molten state.The purity and spray of Ag 28 Cu filler produced using the continuous casting technique can reach the first level.