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Quick Search     Adv Search   2017 Vol. 27, No. 02 Published: 2017-04-10   1 Preparation of injection molded IN713C alloy WU Wei，LI Du-xin，YANG Wen-yan，LU Ren-wei，YANG Zhong-chen DOI: 10.13228/j.boyuan.issn1006-6543.20160022 In order to find a kind of alloy material suitable for the high temperature environment of the gasoline engine turbocharger， the IN713C alloy was chosen as the research object， aiming at exploring the best parameters of IN713C injection molding process. The density， microstructure and mechanical properties of the prepared samples were tested and analyzed. It is found that 850 ℃ is the better pre-heating temperature. When the sintering temperature is 1 300 ℃ and the dwell time is 3 h， the density， hardness and tensile properties of the samples are the best. The sintered density is 7.83 g/cm3， and the relative density is 99.0%. 2017 Vol. 27 (02): 1-5 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 6 Process study of Al2O3 dispersion strengthened copper powders prepared with waste cupric liquor SHI Yong-liang，LIN Tao，YANG Xiao-cai，SHI Yan-lin，LI Xiu-min DOI: 10.13228/j.boyuan.issn1006-6543.20160016 Using acidic and alkaline waste cupric liquor as raw material， the copper solution was prepared with the processes of acid and alkali neutralization， filtration and sulfuric acid dissolution. Then， the soluble aluminum salt was added into the copper solution. Finally， the nano-Al2O3-dispersed strengthening copper-based powders with 2% (mass percent) alumina were prepared with the methods of complex chemical co-precipitation， calcination and hydrogen reduction. The Cu2+ content in filtrate was measured by flame atomic absorption spectrometry， and the influences of mixing ratio of acidic and alkaline waste cupric liquor on the Cu2+ extraction efficiency were studied. The particle size， morphology and composition of precursor powder， Al2O3-CuO composite powder， Al2O3-Cu powder and Al2O3 dispersed phase were analyzed through scanning electron microscope and X-ray diffraction. The calcination and hydrogen reduction processes were analyzed with TG-DTA test. The results show that， neutralization reaction is completed fully when acidic and alkaline waste cupric liquor has the volume ratio of 2 to 3， and Cu2+ extraction efficiency is 96.75% (mass percent). Precursor powder with fine particle size and no agglomeration is obtained by the way of rapid?precipitator addition. The optimum calcination and hydrogen reduction temperature is 500 ℃ and 550 ℃， respectively. The dispersion phase distributes uniformly and the particle size is less than 200 nm. The extraction experiments prove that the dispersed phase is nano Al2O3. 2017 Vol. 27 (02): 6-11 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 12 Numerical simulation of the Fe-based powder metallurgy hydraulic motors valve plate compaction SHAO Rui，ZUO Peng-jun，ZHANG Jiang-xue，YANG Cong-bin，WANG Liu-yong DOI: 10.13228/j.boyuan.issn1006-6543.20160051 Forming process of Fe-based powder metallurgy hydraulic motors valve plate was simulated with the numerical simulation software DEFORM-3D. The local and overall valve plate density distribution was studied under the condition of five different forming process parameters. The basic reason of non-uniform density distribution in the outer step and inner step of the valve plate and the whole was also analyzed. The better forming process parameters were obtained， and the production process parameters were verified. It has important significance to improve the rationality of the process design for the similar powder metallurgy parts. 2017 Vol. 27 (02): 12-19 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 1 ) 20 Effect of 6061Al matrix particle size on microstructure and properties of SiCp/6061Al composites YAN Li-peng，YUAN Guo-sen，DING Hai DOI: 10.13228/j.boyuan.issn1006-6543.20160067 The SiCP/6061Al composites with three kinds of matrix particle size were produced through powder metallurgy method. The effect of 6061Al matrix particle size on microstructure and properties of SiC/6061Al composites were investigated. The results show that， with the increase of matrix particle size， the distribution of reinforcement particles is more and more uneven， the agglomeration phenomenon is obvious， and the density and tensile strength of the composite decrease. 2017 Vol. 27 (02): 20-23 [Abstract] ( 1 ) HTML (1 KB)  PDF  (0 KB)  ( 3 ) 24 Effect of VC content on the microstructure and mechanical properties of Mo2FeB2 based cermets PENG Jia-jian，CONG Shan-hai，TAO Ze-xu，WANG Xiao-feng DOI: 10.13228/j.boyuan.issn1006-6543.20160072 Mo2FeB2 based cermets samples with different VC content were prepared by reaction boronizing sintering. The microstructure and mechanical properties of the samples were analyzed. Results show that VC effectively refines grain size of Mo2FeB2 cermet and is uniformly distributed in the matrix. The hardness and wear resistance of the sample increase firstly and then decrease with the increasing VC content. The sample has the highest hardness and the best wear resistance when the mass percent of VC is 9%. 2017 Vol. 27 (02): 24-27 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 28 The effect of filling temperature on microstructure and properties of FGH97 PM superalloy LIU Ming-dong，，LI Ke-min，，HUANG Hu-bao，，SUN Zhi-kun，，HAN Shou-bo，，LIU Jian-tao，，ZHANG Yi-wen， DOI: 10.13228/j.boyuan.issn1006-6543.20160129 The microstructure， impact property， tensile property at room temperature and stress rupture property of FGH97 superalloy at different filling temperature were observed and analyzed. The results show that at filling temperature of 400 ℃ and 500 ℃， microstructure of superalloy has no obvious difference， the properties above meet the technical requirements. At the filling temperature of 500 ℃， the impact toughness and stress rupture property of the alloy are higher than those filled at 400 ℃. 2017 Vol. 27 (02): 28-31 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 32 Study on sintering properties of Cu-Sn powder by orthogonal experiment method CAO Cai-ting，LIU Yi-bo，，XU Liang，SHEN Ning-ning DOI: 10.13228/j.boyuan.issn1006-6543.20160026 Atomized Cu-Sn50 alloy powder with low melting point and high Sn content were prepared by hot pressing test. The effects of sintering temperature， holding time and holding pressure on the sintering properties of the powder were studied using orthogonal test method. Through the range analysis of orthogonal test data， the SEM morphology of the test sample and the observation and analysis of the microstructure， the sintering properties of the samples were measured and the optimal test scheme was obtained. The results show that the Cu-Sn50 alloy powder has good performance at the sintering temperature of 440 ℃， the dwell time of 180 s and the pressure of 10 MPa. 2017 Vol. 27 (02): 32-37 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 38 Analysis of friction and wear properties of copper-based powder brake linings for train braking ZHANG Jun-feng，DENG Lin DOI: 10.13228/j.boyuan.issn1006-6543.20160034 The braking performance of the train is closely related to the friction and wear performance of the brake linings material. The friction and wear characteristics of self made copper based powder train brake material at different braking speeds were tested on a MM-1000II friction tester. The results show that with the increase of braking speed， the micro bulge on the friction surface is destroyed， the friction coefficient decreases and the wear loss increases. A large amount of friction heat is generated on the contact surface of the material， which results in the softening of the matrix and reduces the clamping ability of the matrix to the hard particles such as SiO2. The friction coefficient and stability coefficient decrease with the increasing braking speed； while the friction temperature and the wear loss increase with the increasing braking speed， especially when the braking speed is greater than 8 r/s， the rising friction surface temperature leads to the matrix softening and the hard particles falling， thus accelerates the friction and wear of materials. It provides a theoretical basis for the study on the friction and wear properties of copper based powder brake linings for train braking. 2017 Vol. 27 (02): 38-41 [Abstract] ( 1 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 42 Effect of Ti content on wear resistance of copper-based powder metallurgy friction materials QIN Qun，WANG Tian-guo， HUA Jian-jie DOI: 10.13228/j.boyuan.issn1006-6543.20160114 Copper-based friction material was prepared by powder metallurgy method. The effect of Ti content on wear resistance of the material was investigated. The results demonstrate that， with the increase of titanium mass fraction from 3% to 12%， the relative density and the hardness of copper based friction material increase. The addition of titanium leads to lattice distortion and the hardness of the material increase. The friction coefficient decreases with increasing of friction velocities. The friction coefficient and the wear extent decrease with the increasing Ti content. The reason is that with the addition of Ti， the hardness of the material is increased， the strength of the surface micro convex body is increased， the degree of ploughing is reduced， the damage degree of the friction surface is reduced， and thus the wear resistance of the material is improved. 2017 Vol. 27 (02): 42-46 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 47 Effect of fishscale and surface roughness on magnetic properties of Fe-based amorphous wide ribbons FU Xiao-tong， CHEN Wen-zhi， YUE Ya-nan， XING Yan-xing， WANG Jian DOI: 10.13228/j.boyuan.issn1006-6543.20160010 The effect of fishscale and surface roughness on magnetic properties of Fe-based amorphous wide ribbons was investigated. Core loss and exciting power of the ribbon are reduced 50%-100% with fishscale. The ribbon has higher core loss and exciting power as the surface roughness increases. 2017 Vol. 27 (02): 47-50 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 51 Preparation and electrochemical performance of Ni2+-doped MOF-5 crystals GUO Yu，LIU Yong DOI: 10.13228/j.boyuan.issn1006-6543.20160085 Metal organic frameworks (MOFs) have become a hot topic in the research of supercapacitor?electrode?materials because of its high specific surface area and tunable pore structure. MOF-5 crystals were synthesized by hydrothermal method using zinc nitrate (Zn(NO3)2·6H2O) and terephthalic?acid (C6H4(COOH)2， BDC) as reactants. The composites of Ni-doped MOF-5 crystals with various additions of Ni ions were obtained. The morphology and microstructure of the as-prepared samples were characterized by scanning electron microscope (SEM) and X-ray diffraction analysis (XRD)， and electrochemical properties used as electrode materials for supercapacitors were tested using the Princeton workstation and Arbin systerm. The results show that the composites of Ni-doped MOF-5 with different morphologies are obtained with various additions of Ni ions. The composite presents uniform Ni-rich microsphere particles when the ratio of Ni ions and Zn ions is 0.50∶1.00 (mole ratio)， and it has good electrochemical performance with a specific capacitance of 400 F/g at a current density of 0.05 A/g. 2017 Vol. 27 (02): 51-57 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 3 ) 58 Effect of WC particle size on the microstructure and properties of WC-CoCr coatings prepared by high velocity oxy-fuel spraying WANG Da-feng，ZHANG Bo-ping，JIA Cheng-chang，GAO Feng，YU Yue-guang，ZHAO Xiao-lin，BAI Zhi-hui DOI: 10.13228/j.boyuan.issn1006-6543.20170024 WC-CoCr coatings with three kinds of microstructure of nanostructure， bimodal and conventional were fabricated by HVOF spraying. The influence of WC particle size on decarburization， microstructure and mechanical properties of coatings were discussed. Results show that， with the WC particle size decreasing， the decarburization rate of coating increases， the content of W2C increases， the coating porosity decreases， the micro-hardness of the coating and bonding strength of the interface increases. Nevertheless， more serious amorphization of binder in the nanostructured coating causes significant fracture toughness deterioration. Bimodal WC-CoCr coating combines the best fracture toughness as well as higher micro-hardness and interfacial bonding strength since reasonable collocation and synergistic effect of nano-sized and submicron-sized WC particles. 2017 Vol. 27 (02): 58-65 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 66 Research progress on synthesis methods of micro/nano chromium nitride powder YANG Bao-zhen， ZHAO Zhi-wei， CHEN Fei-xiao DOI: 10.13228/j.boyuan.issn1006-6543.20160113 The properties and applications of transition metal nitride and chromium nitride powder were presented. Specially， the development of different preparation methods of micro/nano chromium nitride powder was reviewed and the advantages and disadvantages of these methods were estimated. Further development of synthesis methods for chromium nitride in the future was also suggested. 2017 Vol. 27 (02): 66-72 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 1 ) 73 Study of hydrophobic graphene composite plastics used for air conditioning heat exchange surface treatment REN Chun-li，GENG Xiao-xin，WU Hong-peng DOI: 10.13228/j.boyuan.issn1006-6543.20160139 Plastics are widely used in various fields due to their low cost and light weight. However， in the processing and use of plastic products， it is easy to produce static electricity because of friction， which not only causes the impact of dust on the plastic surface， but leads to electrostatic sparks， even causes explosion or fire. Graphene was used as conductive agent to solve the problem of affinity between graphene and polycarbonate (PC) matrix and the inherent static problems of plastics， while improving the thermal conductivity， wear resistance， anti-aging properties of plastics. The liquid phase composite method and melting process were used to make the graphene dispersed into plastic polycarbonate matrix. The preparation of graphene composite plastic products which can be used to treat the heat exchange surface of the air conditioner is carried out. 2017 Vol. 27 (02): 73-77 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 3 )

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