Ma Qin, Kang Mokuang. New Advance in High-Temperature Structural Silicides Research[J]. Journal of Materials Engineering, 1997, 0(7): 3-6.
New research adveance in the MSi2and M5Si3(M=Mo,Nb,Ti) type refractory metallic silicides as a new class of high-temperature structural materials are overviewed,and the synergistic toughening effeet of SiC whiskers and ZrO2 particles on MoSi2,according to author's the newest research results,is exhibited.It is pointed out that combining the preparing composites with alloying in MoSi2 modification researches,in particular,combining the matrix modification with in-situ compounding together,as well as paying attention to the research on the MoSi2 matrix nanocomposites and the synergistic effects of various reinforcements in MoSi2 composites,are main developing research trends for improving the mechanical properties of MoSi2 compound.Moreover,for the M5Si3type silicides the research on the two-phase Nb-Nb5Si3and Ti-Ti5Si3 alloys,and boron-doped Mo5Si3matrix materials are more spectacular.
Zou Xiaoping, Zhang Liangying, Yao Xi, Wang Likun, Zhang Fuxue. Preparation and Piezoelectric Property of 0-3 Piezoelectric Ceramic-Polymer Composites[J]. Journal of Materials Engineering, 1997, 0(7): 7-10,22.
The flexible piezoelectric composites PZT-PVDF are prepared by embedding piezoelectric ceramic PZT particles into PVDF matrix.In order to improve hydrostatic piezoelectric sensitivity,another flexible piezoelectric composites PT-P(VDF/Te FE) are prepared by embedding piezoelectric ceramic PT particles into P(VDF/Te FE) matrix,due to strong anisotropy of piezoelectric ceramic PT.The preparation and hydrostatic piezoelectric properties of the two composites are reported.The applications of PT-P (VDF/Te FE) in underwater device field are discussed.
Qu Xuanhui, Yan Hansong, Li Yimin, Mao Jinying, Qiu Guanghan, Li Zhilin. Estimation of Properties for Polymers in MIM Binder[J]. Journal of Materials Engineering, 1997, 0(7): 11-13,32.
Some estimating approaches to the properties of polymers in MIM binder are introduced and the surface properties of some binders are investigated.
Mi Guofa, Luo Zhiping, Tian Shifan. Tensile Properties and Fracture Characteristics of Spray-Deposited IC6Alloy[J]. Journal of Materials Engineering, 1997, 0(7): 14-16.
Testing for tensile properties indicated the spray deposited IC6alloy also possesses "R" characteristic in the yield and tensile strength;Analysis of cracking by stereographic projection shows that alloy cracks along the plane {111} of octahedral system of slide.
Zhang Zhonghua, Sun Yangshan. Relationship Between Microstructure and Mechanical Properties of Fe3Al-Based Alloy[J]. Journal of Materials Engineering, 1997, 0(7): 17-19.
Microstructure has complex effect on tensile at room temperature and 600℃ and creep properties of Fe3Al-based alloy.The ductility at room temperature can be improved significantly by grain refinement resulted from more deformation during warm rolling,but reducing tensile at 600℃ and creep properties.It is found that reducing transverse grain boundaries is not the most effective way to improve ductility at room temperature.
Zhang Shichao, Qiu Xueliang, Ma Changwen. The Oxidation Behavior of the Carbon Derived from the Formaldehyde Resin[J]. Journal of Materials Engineering, 1997, 0(7): 20-22.
The oxidation behavior of the carbon derived from the thermoplastic formaldehyde resin has been studied.The experiment results showed that the oxidation rate of the carbon increases with the burn-off of the carbon,and decreases with the heat treatment temperature.The activated energy of the oxidation of the carbon was about 20 kcal/mol when the heat treatment temperature changed between 800℃ and1 600℃,and was 34 kcal/mol when the temperature was at 1950℃.The decrease of the oxidatlon rate with the heat treatment temperature only resulted from the variation of the BET surface area of the carbon when the heat treatment temperature changed between 800℃ and 1600℃.
Liu Ying, Deng Bo, Chen Gansheng, Zhong Zengyong. Optimization of Microstructure and Rupture Strength of GH90 7Alloy Using D-Electron Alloy Design Theory[J]. Journal of Materials Engineering, 1997, 0(7): 23-25,29.
It was discovered that the stability of matrix γ and γ'phase was notably affected by the Si content in GH907.A high content of Si can result in the precipitation of Laves phase and the increment of εphase.Proper types and volume fraction of precipitates are beneficial to rupture strength.A comprehensive evaluation of phase stability of the alloys was conducted using the d-electron alloy design theory(or the New PHACOMP).It was also proved that the tendency of the precipitation of TCP phase was enhanced with the increment of Si content.The proper range of Mdγ for GH90 7alloy is from0.858to0.867,and the corresponding value of Mdγ'is from 1.112 to 1.132.
Zhang Lefu, Xie Changsheng, Zhang Yizeng. Computer Aided Material Selection System[J]. Journal of Materials Engineering, 1997, 0(7): 26-29.
A new material selector,based on material scientific database,is introduced.This system is designed under the rule of expandable structure.By analyzing the concepts in material science and technology,the material database is cut into three parts:basic material data which only depend on the composition,process parameters and properties involved in materials processing,and commercial information about material products.Through registering the process parameters and properties of material application systems into materials scientific database,the relationship between material,process and properties is established,and therefore it comes into reality that the engineers can simultaneously select materials and planning the process.And this laid a solid foundation for this system to become a supporting material selection system for CAD/CAE/CAM/CIMS software packages.
Yu Qian, Xiao Chengbo, Tan Yongning, Zhao Xihong. Effect of Ageing Temperature on Microstructure and Properties of Superalloy K77[J]. Journal of Materials Engineering, 1997, 0(7): 30-32.
The effect of ageing temperatures on microstructure and properties of cast Nibase superalloy K77 with optical metalloscope,SEM,EDS and TEM was studied.The results showed that the carbide reaction occurred in different degree at three ageing temperatures and the higer temperature caused the faster reaction so that the quantity of M23C6and γ' increased.The stress-rupture life at 980℃/150 MPa decreaed with increasing aged time at 760℃,but that increased with increasing aged time at 815℃ and 870℃.The results were related to the cooperative strengthening role of γ'phase and M23C6.
Jiang Hai, Yuan Zhenghua, Xu Jianxiang, Yang Ronghua. The Manufacturing of Symmetric-Nonbalanced Laminate with Certain Sublaminate[J]. Journal of Materials Engineering, 1997, 0(7): 33-35.
Through the manufacturing of the skin of composite rudder with the Nomex honeycomb sandwich construction,the characteristics of the symmetric-nonbalanced laminate with certain sublaminate have been analyzed.And the approach with which the fiber volume content in the cured laminate and the deformation quantity relative to mold surface can be ensured to accord with the design requirments have been pointed out.
Liu Baofeng, Chen Hongjun, Li Peilan. Research on the Technology Stability of the 48" Woven Prepreg Machine by Solution Method[J]. Journal of Materials Engineering, 1997, 0(7): 36-38.
This article puts emphasis on the contrast of properties of various batches prepregs,and finally evaluates the technology stability of 48" woven prepreg machine by solution method.
Han Yongcai, Lu Jinggui. A Study of Inner Sealant of Insulating Glass and Moulding Process[J]. Journal of Materials Engineering, 1997, 0(7): 39-40.
Selecting and moulding of inner sealant for insulating glass is presented.Properties test shows that the inner sealant is qualified to the requirements of similar foregin products.
Chen Chinan, Yu Rongli, Han Haijun, Su Mei. Failure Analysis and Prevention for Gear Boxes[J]. Journal of Materials Engineering, 1997, 0(7): 41-44.
Failure analysis of gear boxes was carried out by means of SEM,metallographic examination,mechanical properties test,and calculation.It was found that this failure is fatigue fracture caused by fretting wear.The preventing measures were suggested.
Feng Weixi. The Designation and Condition Coding of Metallic Materials in Europe(AECMA)[J]. Journal of Materials Engineering, 1997, 0(7): 45-49.
The designation system of metallic materials in AECMA was introduced in this paper.The coding of conditions in metallic materials was also presented.And some examples were shown.
