Home  |  About Journal  |  Editorial Board  |  Instruction  |  Subscribe  |  Advertisement  |  council  |  Contact Us  |  中文

Forthcoming Articles       Current Issue       Advanced Search       Archive       Download Articles       Read Articles       Email Alert

Quick Search     Adv Search   2018 Vol. 28, No. 02 Published: 2018-04-10   1 Research progress of hot isostatic pressing technology of titanium alloy powder LIU Wen-bin，，CHEN Wei，，WANG Tie-jun，，CHE Hong-yan，，LIANG Chao， DOI: 10.13228/j.boyuan.issn1006-6543.20170129 The development history of powder titanium alloy prepared by hot isostatic pressing technology for more than 60 years and the present situation of research and development in the world were reviewed. The problems encountered in the market development in the field of aerospace were analyzed， and the solutions were also put forward. At last the future trends of the technology were presented. 2018 Vol. 28 (02): 1-7 [Abstract] ( 2 ) HTML (1 KB)  PDF (2511 KB)  ( 4 ) 8 Characterization of W-Cu composite powder for vehicle electrode prepared by hydrothermal co-reduction method WANG Wei，WANG Jun，ZHANG Xiao-xu DOI: 10.13228/j.boyuan.issn1006-6543.20160106 In order to improve the electrical conductivity of the vehicle electrode， the W-Cu composite powder was prepared by hydrothermal reduction method. The morphology and phase composition of the composite powder were characterized by SEM and XRD. The characteristics of the composite powder after hydrothermal reaction， calcination and reduction were analyzed. Results show that the precipitate shows a particle agglomeration state with different sizes after hydrothermal reduction reaction. The powders are spherical and the particle size is about 2.5 μm， mainly composed of CuWO4H2O and Cu2WO4（OH）2， which indicates that the products produced in the hydrothermal reaction stage have obvious crystalline structure. There is a large amount of[CuWO4-x]in the calcined powder， which is composed of[CuWO4-x，]CuO and WO3. The reduced powder has agglomeration phenomenon and small initial particles. The reduced Cu particles play a catalytic role to the reduction of WO3， finally the W-Cu composite powder with dispersed distribution and fine particles are formed. 2018 Vol. 28 (02): 8-11 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 12 Effect of different forming processes on ultrasonic defect signals of Ni-based powder metallurgy superalloy SUN Zhi-kun，，Lü Ri-hong，JIA Jian，，HAN Shou-bo，，ZHANG Yi-wen，，XIE Ling， DOI: 10.13228/j.boyuan.issn1006-6543.20160124 Contact ultrasonic testing of FGH4096 alloy rings formed by hot isostatic pressing and forging or direct hot isostatic pressing was carried out respectively. The results indicate that there are obvious defect signals when inspecting along the cylindrical surface of the ring prepared by hot isostatic pressing and forging method， and the highest signals appear at the center of the axial thickness； the height of the defect signals gradually reduces down when close to the terminal face； the defect signals still exist near the surface； there are defect signals along all of the outer circumference， and the characteristics of the signals are the same， which is similar to cracks； the location of the signals is almost invariant along the radial direction. While there is no similar defect signal when inspecting FGH4096 ring blank prepared by direct hot isostatic pressing. The experimental results show that the defect signals found along all of the outer circumference of the forging ring is a pseudo defect. It is due to the small attenuation coefficient and the high pulse repetition frequency. 2018 Vol. 28 (02): 12-17 [Abstract] ( 1 ) HTML (1 KB)  PDF  (0 KB)  ( 1 ) 18 Effects of laser parameters and scanning strategy on the forming properties of selective laser melting TC11 alloy XIE Yan-jun，，YANG Huai-chao，WANG Xue-bing，KUANG Chun-jiang，，HAN Wei DOI: 10.13228/j.boyuan.issn1006-6543.20170144 TC11 alloy samples were prepared by selective laser melting technology. The influence of laser parameters and laser scanning strategy on the forming properties of TC11 alloy was investigated. The results indicate that， with the increase of laser scanning speed， the metal spherical particles adhering to the alloy surface increase， the width of single scanning molten pool decrease， and the surface of the sample becomes much coarser. There are spherical pores exist in the sample when the laser scanning speed is 0.6 m/s， while there are irregular pores exist in the sample when the laser scanning speed is greater than 1.2 m/s. With the increase of laser power， the width of single scanning molten pool increase and the surface of the samples become much smoother. There are little small irregular pores inside the sample when the laser power is not higher than 280 W， while there are little small spherical pores inside the sample when the laser power is 320 W. The scanning strategy of each layer is rotated 67 degrees relative to the previous layer makes up for the height difference between the center and edge caused by the previous scanning layer， avoiding the height difference increase， thus avoiding the internal porosity. The research provides a basis for selecting appropriate laser parameters and scanning strategy for preparing TC11 alloy by selective laser melting. 2018 Vol. 28 (02): 18-24 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 3 ) 25 The first-principles study on the elasticity of[Ti1-xWxC(x=0~1.00)]solid-solution carbides PANG Li-juan，DENG Gang，ZHANG Xue-feng，XIAO Hong DOI: 10.13228/j.boyuan.issn1006-6543.20160126 The lattice constants， elastic properties and electronic densities of[Ti1-xWxC][（x＝]0， 0.10， 0.20， 0.30， 0.40， 0.50， 0.75， 1.00） were calculated using the first-principles method based on the density functional theory. Results show that the calculated results are consistent with the experimental data reported. It is found that the lattice constant of[Ti1-xWxC]decreases linearly with the increase of tungsten content. Ti0.60W0.40C has a maximum shear modulus of 237.46 GPa， while Ti0.50W0.50C has the lowest[G/B]value of 0.59， and its toughness is the best. The results of electron density analysis show that these compounds have obvious pd orbital hybridization effect except WC， which leads to the change of mechanical properties. 2018 Vol. 28 (02): 25-29 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 1 ) 30 Study on radiation resistance of domestic B4C particle reinforced aluminum matrix composite SHI You，LIU Gui-rong，ZHANG Ya-dong，NING Dong，CHEN Jin，YANG Yi-zhong DOI: 10.13228/j.boyuan.issn1006-6543.20170126 The B4C particle reinforced Al-matrix composite used as neutron absorber plates were prepared by powder metallurgy method. After being subjected to a radiation test with fast neutron influence up to 4.22×1019 n/cm2 and gamma-ray dose reaching 4.75×1011 rad， the properties of the material， including surface morphology， size， mass， density， mechanical properties （tensile strength， hardness and elongation） as well as boron-10（10B） areal density， were tested and compared with those before irradiation. The results show that the tensile strength and hardness of the composite are improved with the elongation decreased， the surface morphology has not changed obviously， and the size， mass， density and 10B areal density have not changed significantly under the irradiation of neutron and gamma rays. 2018 Vol. 28 (02): 30-34 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 35 Influence of dewaxing process on the performance of diamond bit XU Qiang，LIU Yi-bo，，XU Liang DOI: 10.13228/j.boyuan.issn1006-6543.20160122 The effect of dewaxing process on the performance of diamond bits was studied by comparing dewaxing process with non-dewaxing process. The results show that the density， hardness and bending strength of the cutter head are improved by the dewaxing treatment. For both formulations， the sharpness and life of the dewaxed bit are both improved. Meanwhile， after dewaxing， the content of C and O elements in the cutter head is obviously reduced， and the residue of the granulating agent in the cutter head is reduced， so that the comprehensive performance of the drill bit is improved. 2018 Vol. 28 (02): 35-38 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 39 Finite element analysis for the effective thermal conductivity of copper foam LI Yu，SHEN Wei，ZHAO Peng，PU Yu-ping DOI: 10.13228/j.boyuan.issn1006-6543.20160112 With the aid of X-ray micro-computed tomography and digital image processing technology， three-dimensional structure of copper foam prepared by electro deposition process was reconstructed. Furthermore， a simplified finite element model of copper foam was proposed， which can reflect the structure of copper foam more truly. On the basis of Fourier heat conduction equation， the finite element method was applied in finite element analysis for the effective thermal conductivity of copper foam. In the meanwhile， a quantitative relation between effective thermal conductivity and porosity of the copper foam was established， and the relationship between the thermal stress and the single cell model of copper foam was studied. 2018 Vol. 28 (02): 39-44 [Abstract] ( 1 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 45 Effect of tensile deformation on the microstructure and properties of high-entropy alloy laser cladding coating WEN Li-zhe，HUANG Yuan-sheng，LIN Jin-wen DOI: 10.13228/j.boyuan.issn1006-6543.20160107 Al2CoCrCu0.5FeMoNiTi high-entropy alloy laser cladding coating was synthesized on stainless steel and 40Cr steel with laser cladding equipment. The coating was annealed and stretched， and was tested by X-ray diffractometer， scanning electron microscope and microhardness tester. Results show that the coating shows granular structure after polishing and aqua regia corrosion. The hardness of the coating is not affected by annealing at 300 ℃， while the hardness of the coating increases after annealing at 500-700 ℃， indicating that the coating has an aging effect. The cladding coating is composed of bcc single phase， and the coating maintains a stable phase structure after annealing at 300 ℃. After tensile deformation， the diffraction peak intensity of the coating increases and the grain boundary is clear. The hardness decreases firstly and then increases with the increase of deformation. The coating has good adhesion， except that the coating near the fracture surface is peeling. 2018 Vol. 28 (02): 45-48 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 49 Effect of Dy content variation on grain boundary diffusion of Nd-Fe-B base magnet LI Jian，， CHENG Xing-hua， ZHOU Lei， LIU Tao， YU Xiao-jun， LI Bo DOI: 10.13228/j.boyuan.issn1006-6543.20170011 Several Nd-Fe-B sintered magnet samples with different Dy contents which ranges from 0-4.00%（mass percent） were prepared and were used as a base magnet for Dy GBDP （Grain boundary diffusion process）. The magnetic properties， chemical composition and microstructure of the samples were analyzed and compared. It is found that the coercivity of the samples all increase 263.4-316.7 kA/m and Dy contents increase 0.30%-0.35% （mass percent）， but the increments are not controlled by Dy content in base magnet directly. A further investigation show that， the[Hcj]increments are not proportional to the Dy increments， and the[Hcj]increase rate per Dy amount decreases gradually along with the increase of Dy content in base magnets. Considering another factor-EPMA Dy mapping images， Dy diffusion in Dy-free magnet results in a critical transformation of grain boundary structure， which is transformed from Dy-free structure to Dy-containing structure， and it makes the highest[Hcj]increase rate. 2018 Vol. 28 (02): 49-53 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 54 Study on friction and wear properties of phenolic resin based water lubricated bearing materials HUANG Xia，ZHENG Yong-xiang，YIN Xiang，GE Ke，LIU Yi-bo，XU Yan-jun DOI: 10.13228/j.boyuan.issn1006-6543.20160132 The phenolic resin was used as a matrix， and PTFE， potassium hexatitanate whiskers and nano alumina were added for modification； A special process was adopted to compound the copper alloy and the phosphorus-copper alloy mesh to prepare a metal matrix layer； The phenolic resin modified material was compounded on the metal matrix by hot pressing and curing process to prepare the working layer of the water-lubricated bearing material with a metal-plastic composite structure. The tribological properties of the material in water medium were studied. The results show that the sample has the lowest friction coefficient when the content of PTFE is the highest； the sample has the smallest wear depth when the amount of potassium hexatitanate whisker is the largest； while the friction coefficient and the wear depth is both the highest when nano-alumina is added at the maximum. It indicates that PTFE and potassium hexatitanate whiskers are beneficial to improving the tribological properties of phenolic resin， while the addition of nano-alumina decreases the tribological properties of phenolic resin. 2018 Vol. 28 (02): 54-57 [Abstract] ( 1 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 58 Research status of preparation technology of spherical titanium and titanium alloy powders TANG Xin，LI Ai-hong，LI Bo DOI: 10.13228/j.boyuan.issn1006-6543.20160111 Spherical titanium powder has the characteristics of high sphericity， good fluidity， high loose density and low oxygen content. The basic principle and current research status of several common preparation processes of spherical titanium powder were introduced， including atomization method， plasma rotation electrode process， plasma torch atomization method and radio frequency plasma spheroidization method. The atomization method is the main production method of spherical titanium powder， including inert gas atomization and centrifugal atomization method. The inert gas atomization method has the characteristics of high production efficiency， wide particle size distribution and high recovery rate of fine powder， which is the main method of producing spherical titanium powder at present. The powder produced by plasma rotary electrode has the characteristics of high sphericity and good fluidity， but low recovery of fine powder. The plasma torch atomizing method can produce titanium powder with high sphericity and good fluidity， but the production cost is higher. The titanium powder produced by radio frequency plasma spheroidization method has the characteristics of high sphericity and good fluidity， but the method has low production capacity. Finally， the powder characteristics of several processes were compared， and the problems in the preparation process of spherical titanium powder were pointed out. The preparation and development direction of spherical titanium powder were prospected. 2018 Vol. 28 (02): 58-64 [Abstract] ( 0 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 65 Research progress on preparation and application of pre-alloyed powder for diamond tools GAO Ya，ZHONG Su-juan，JIU Yong-tao，SUN Hua-wei，ZHANG Jing-chao，DING Tian-ran DOI: 10.13228/j.boyuan.issn1006-6543.20170137 The technological process， advantages and disadvantages of various methods for preparing pre-alloyed powder by atomization， hydrometallurgy and mechanical alloying were introduced briefly. The application of pre-alloyed powder in brazing diamond tools， laser welding diamond tool transition layer and diamond tool head matrix was analyzed comprehensively. The research situation of domestic and foreign researchers and enterprises in related fields was also briefly introduced， and the development trend of pre-alloyed powder for diamond tool industry was predicted. 2018 Vol. 28 (02): 65-71 [Abstract] ( 1 ) HTML (1 KB)  PDF  (0 KB)  ( 2 ) 72 Performance evaluation of resin-based brake pads LIU Li，ZHONG Li，ZHANG Jie，LONG Chan-juan DOI: 10.13228/j.boyuan.issn1006-6543.20170152 Aluminum silicate ceramic fiber / copper fiber reinforced resin-based brake pads were prepared by dry method. The friction coefficients， wear rates and the mechanical-physical properties were appointed as performance indicators. The multi-layer fuzzy comprehensive evaluation was employed to screen out the best formula. Wear mechanism was analyzed by microstructure analysis of worn surfaces， and the influence of different mass of alumina-silicate ceramic fiber/copper fiber on resin-based brake pads was explored. The results show that the fuzzy comprehensive evaluation value of formula F3 （10% aluminum silicate ceramic fiber/15% copper fiber， mass percent ） is the highest and the comprehensive performance is the best. With the decrease of copper fiber content and the increase of aluminum silicate ceramic fiber content， the main wear mechanism gradually changes from abrasive wear to adhesive wear， thermal wear and fatigue wear. 2018 Vol. 28 (02): 72-77 [Abstract] ( 1 ) HTML (1 KB)  PDF  (0 KB)  ( 1 ) 78 Research on processing technology of transmission fine adjustment mechanism based on plasma flame cutting machine ZHOU Yan，LI Xiao-long，ZHAO Zhi-feng，LI Yu-min DOI: 10.13228/j.boyuan.issn1006-6543.20170127 Due to the instability of the transmission mechanism of the plasma flame cutting machine in the transmission process， the precision of the processed product cannot meet the design requirements. The transmission mechanism of plasma flame cutting machine is the main reason for producing machining error. By designing and changing the adjusting mode of the transmission mechanism， the redundant degree of freedom is limited， and the movement of the transmission case is adjusted by utilizing the elastic pin coupling and the limiting spring， so that the transmission gear is accurately meshed with the rack， the tooth direction dislocation and the beating are avoided， and the stability and the accuracy of the cutting head in the cutting process are ensured. The improved equipment is applied to the process of gear precision machining， results show that the qualified rate of the product is increased to 98%， the processing cost is reduce by 57%， the processing period is shortened by 50%， the dependence on a high-performance special machine tool is reduced， the economic benefit is greatly improved， and the method has certain market popularization value in the processing of similar parts. 2018 Vol. 28 (02): 78-81 [Abstract] ( 2 ) HTML (1 KB)  PDF  (0 KB)  ( 1 )

Copyright © Editorial Board of Powder Metallurgy Industry Supported by:Beijing Magtech