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Effect of carbide formers on microstructure and thermal conductivity of diamond-Cu composites for heat sink materials

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中国有色金属学会会刊：英文版 2009年第5期19卷 1161-1166页

作者：夏扬宋月清林晨光崔舜方针正 General Research institute for Nonferrous metals

Diamond-copper composites were prepared by powder metallurgy,in which the diamond particles were pre-coated by magnetic sputtering with copper alloy containing a small amount of carbide forming elements(including B,Cr,Ti,and Si).The influence of the carbide forming element additives on the microstructure and thermal conductivity of diamond composites was *** is found that the composites fabricated with Cu-0.5B coated diamond particles has a relatively higher density and its thermal conductivity approaches 300 W/(m·K).Addition of 0.5%B improves the interfacial bonding and decreases thermal boundary resistance between diamond and Cu,while addition of 1%Cr makes the interfacial layer break away from diamond *** actual interfacial thermal conductivity of the composites with Cu-0.5B alloy coated on diamond is much higher than that of the Cu-1Cr layer,which suggests that the intrinsic thermal conductivity of the interfacial layer is an important factor for improving the thermal conductivity of the diamond composites.

关键词：铜复合材料硬质合金导热系数钻石显微结构散热片金刚石复合材料金刚石颗粒

Tensile and Fracture Properties of 15 vol% SiC_p/2009Al Composites Fabricated by Hot Isostatic Pressing and Hot Extrusion Processes

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Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 875-884页

作者： Junhui Nie Jianzhong Fan Shaoming Zhang Shaohua Wei Tao Zuo Zili Ma Zhaobing Xiang General Research institute for Nonferrous metals

15 vol% silicon carbide particle （SiCp）-reinforced 2009A1 matrix （15 vol% SiCp/2009A1） composites were fabricated by hot isostatic pressing （HIP） and hot extrusion processes. The tensile and fracture properties of 15 vol% SiCp/ 2009Al were studied. The results showed that hot extrusion increased the ultimate tensile strength （UTS）, yield strength （YS）, elongation （EL）, reduction in area （RA）, and fracture toughness of the composites. The heat treatment resulted in the increase in UTS, YS, and fracture toughness, but a decrease in EL and RA. Both hot extrusion and heat treatment had negligible effects on elastic modulus （E）. With the increase of SiCp size, the UTS, YS, and E decreased, but the EL and RA increased. The fracture toughness increased first and then decreased with increasing SiCp size, and when the SiCp size was about 7 μm, the composites obtained the maximum fracture toughness value of 31.74 MPa m^1/2.

关键词： Aluminum matrix composites Silicon carbide Tensile properties Facture toughness Particle size

Effects of microstructure on creep behavior of Mg-5%Zn-2%Al(-2%Y) alloy

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中国有色金属学会会刊：英文版 2008年第3期18卷 580-587页

作者：邹宏辉 General Research institute for Nonferrous metals

Creep tests of Mg-5%Zn-2%Al(-2%Y) (mass fraction) alloy were carried out at 175 ℃ under the load of 50 MPa, on the cast and solution condition, respectively. Relationship between the creep behavior and microstructure was studied by the optical microscopy, SEM and TEM. The result shows that the primary creep strain is relative to the thermo-stability and the quantity of intermetallic compounds in grain boundary area. During the secondary creep period, the minimum creep rate of solution-treated specimens is substantially decreased as a result of dynamic MgZn2 precipitation.

关键词：镁合金微结构镁-锌相动力沉淀

Deep drawing of 6A16 aluminum alloy for automobile body with various blank-holder forces

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Rare metals 2019年第10期38卷 946-953页

作者： Zhao-Yang Liu Bai-Qing Xiong Xi-Wu Li Li-Zhen Yan Zhi-Hui Li Yong-An Zhang Hong-Wei Liu State Key Laboratory of Nonferrous metals and Processes General Research Institute for Nonferrous Metals

Based on the ABAQUS/explicit finite element method,the deep drawing of 6A16 alloy pre-aged and then storaged at room temperature for 1 week with various blank-holder forces(10,14,18 kN) was *** distribution and variation of stress and strain in deformation zones were investigated to drive the forming property and process of the ***,the simulation result was verified combined with the deep drawing *** results show that the stress and strain of the deformation zone have an incremental trend with the blank-holder force increasing while the deformation degree and grain size within a certain deformation zone have an obvious increase and an enlargement,*** the deep drawing,the hardness of products also increases with the enhancement of blank-holder *** blank-holder force of 18 kN is certified as the preferential one by the analysis of microstructure and simulation results.

关键词： ABAQUS 6A16 aluminum alloy Deep drawing test Blank-holder force

Crystallization behavior of Ti_(61.67) Zr_(17.15)Ni_(14.80)Cu_(6.38) glass-forming alloy

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中国有色金属学会会刊：英文版 2004年第1期14卷 156-160页

作者：范金铎高逸群黎仕增 Beijing General Research institute for Non ferrous metals institute of Precious metals Guangxi institute of Mechanical & Electrical Technology

Ti 61.67 Zr 17.15 Ni 14.80 Cu 6.38 (atom fraction, %) metallic glass has applications in brazing. Using the hammer and anvil technique, Ti 61.67 Zr 17.15 Ni 14.80 Cu 6.38 metallic glass was prepared. The crystallization behavior for this metallic glass was investigated by differential scanning calorimetry(DSC), X ray diffractometry(XRD) and transmission electron microscopy(TEM). There are three stages in DSC curves of crystallization. The reduced glass temperature T rg is 0.42. The kinetic parameters of crystallization were calculated by a set of equations of the maximum crystallization rate. The crystalline phase formed in the MSI(Metastable stage I) is Zr 2Cu, in the MSII is α Ti and in the MSIII is Ti 2Ni. This kind of alloy has lower glass forming ability, and the Ti 61.67 Zr 17.15 Ni 14.80 Cu 6.38 metallic glass has lower thermal stability.

关键词：钛合金非晶合金晶化动力学 TEM DSC XRD

As-cast microstructure of Al-Zn-Mg-Cu-Zr alloy containing trace amount of Sc

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Rare metals 2019年第4期38卷 343-349页

作者： Yu Wang Bai-Qing Xiong Zhi-Hui Li Shu-Hui Huang Kai Wen Xi-Wu Li Yong-An Zhang State Key Laboratory of Nonferrous metals and Processes General Research Institute for Nonferrous Metals

It has been reported that the element scandium (Sc) is the most effective modificator which can significantly refine the grain size,prohibit recrystallization process and increase the *** trace of Sc in 7000 series aluminum alloys is considered to be an effective way to modify its microstructure and promote mechanical *** order to study the effect of Sc element on ascast microstructure of Al-Zn-Mg-Cu-Zr alloy,ingots containing different amounts of Sc were prepared by ferrous-mold *** were characterized by means of differential scanning calorimeter (DSC),X-ray diffraction (XRD),optical microscope (OM) and scanning electrical microscope (SEM).The results indicate that when the Sc level exceeds a critical concentration,A13(Sc,Zr) primary phase would form in the melt and act as an efficient nucleant,resulting in very refined grain and an equiaxed grain *** element reduces the number of eutectic phases formed during solidification,coupled with an increase in the concentration of major alloying elements retained in the *** behavior suggests possible benefits in improving the integrated properties of terminal products.

关键词： Scandium Aluminum alloy As-cast Microstructure Nucleant

Dynamic stress–strain properties of Ti–Al–V titanium alloys with various element contents

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Rare metals 2013年第6期32卷 555-559页

作者： Rui Liu Song-Xiao Hui Wen-Jun Ye Cheng-Lin Li Yan-Yan Fu Yang Yu Xiao-Yun Song State Key Laboratory of Nonferrous metals General Research Institute for Nonferrous Metals

A series of Ti–Al–V titanium alloy bars with nominal composition Ti–7Al–5V ELI,Ti–5Al–3V ELI,commercial Ti–6Al–4V ELI and commercial Ti–6Al–4V were *** alloys were then heat treated to obtain bimodal or equiaxed microstructures with various contents of primary a *** compression properties of the alloys above were studied by split Hopkinson pressure bar system at strain rates from 2,000 to 4,000 *** results show that Ti–6Al–4V alloy with equiaxed primary a(ap)volume fraction of 45 vol%or 67 vol%exhibits good dynamic properties with high dynamic strength and absorbed energy,as well as an acceptable dynamic ***,all the Ti53ELI specimens and Ti64ELI specimens with ap of 65 vol%were not fractured at a strain rate of4,000 *** appears that the undamaged specimens still have load-bearing *** strength of Ti–Al–V alloy can be improved as the contents of elements Al,V,Fe,and O increase,while dynamic strain is not sensitive to the composition in the appropriate *** effects of primary alpha volume fraction on the dynamic properties are dependent on the compositions of Ti–Al–V alloys.

关键词： Dynamic properties Alloying content Microstructure Titanium alloy

Hot deformation behavior and globularization mechanism of Ti-6Al-4V-0.1B alloy with lamellar microstructure

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Rare metals 2013年第2期32卷 122-128页

作者： Yang Yu Bai-Qing Xiong Song-Xiao Hui Wen-Jun Ye State Key Laboratory of Nonferrous metals & Processes General Research Institute for Nonferrous Metals

Hot deformation behavior and globularization mechanism of Ti6A14V0.1B alloy with lamellar micro structure were quantitatively studied through isothermal compression tests with the temperature range of 850950 ℃and strain rate range of 0.011.00 s1. The results show that the peak flow stress and steady stress are sensitive to the strain rate and temperature. The value of deformation activation energy is 890.49 kJmo11 in （a＋β） region. Dynamic recrystallization is the major deformation mecha nism. Flow softening is dominated by dynamic recrystallization at 850950 ℃. TiB particles promote the recrystallization of laths. Globularization processes consist of four steps： for mation of subgrain after dynamic recovery in a plates; subgrain boundary migration caused by interracial instability; interfacial migration promoting phase wedge into a phase; disintegrating of a laths by diffusion processes; and grain boundary sliding. Globularization mechanisms during hot deformation processes of the Ti6A14V0.1B alloy with lamellar structure are continuous dynamic recrystallization.

关键词： Ti-6A1-4V-0.1B Hot deformation Lamellarmicrostructure Globularization mechanism

Deposition rate of hafnium crystal bar by iodide process

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Rare metals 2014年第2期33卷 161-165页

作者： Li-Sen Tian Yan-Xi Yin Zhi-Fang Hu Hong-Lin Jiang Zhong-Qi Li Li-Jun Wang Division of Rare metals Materials & Metallurgy General Research Institute for Nonferrous Metals

Single variable and deposition weight methods were adopted in the experiment. The hafnium crystal bar was fabricated by the iodide process. Influence of hafnium filament temperature（K value）, temperature controlling method, types of feed, and the loading methods on the deposition rate were studied. The results show that the K value, temperature control method, types of feed, and the loading methods have obvious effects on the deposition rate of the hafnium crystal bar. The deposition rate increases with the K value rising in the range of certain temperature;the salt bath controlling temperature method could effectively obtain the better deposition rate; the greater the contact areas of the feeds are, the faster the deposition rate ***, the optimal iodide deposition techniques of preparing hafnium crystal bar are as follows： hafnium turnings as feed,molybdenum feed retainer charging, salt bath temperature controlling under the higher K value.

关键词： Iodide process Hafnium Deposition rate