CHEN Yu
,
CHEN Nianyi Shanghai institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
China PENG Ping
,
KONG Bingyu Iron and Steel Research Institute
,
Shanghai Baoshan Iron and Steel Complex
,
Shanghai
,
China professor
,
Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai 200050
,
China
金属学报(英文版)
An alloy steel pattern recognition expert system,ASPRES,has been established for the purpose of computer aided optimal design of alloy steel in compositions and process pa- rameters,Pattern recognition techniques are used to abstract inner relationship between mechanical properties and process variables.The ASPRES uses 2-dimensional graph as visual knowledge to represent domain expertise of specific object.Forward and back- ward chaining can be utilized by researcher in predicting sample performances or giving helpful suggestions about the chemical compositions and process parameters according to desired properties.
关键词:
pattern recognition
,
null
,
null
ZHANG Qiyun
,
LIU Shuqi
,
XU Yaping Peking University
,
Beijing
,
China professor
,
Department of Chemistry
,
Peking University
,
Beijing
,
100871
,
China
金属学报(英文版)
The features of Cu_6Sn_5 growing slowly at lower temperature and growing rapidly up over 350℃,and or Cu_3Sn growing at higher temperatures,bave been detailedly observed under SEM.The increase of Pb content seems to inhibit sequentially the growth of Cu_6Sn_5 in Pb-Sn alloy.
关键词:
Cu
,
null
,
null
,
null
,
null
YIN Weimin GUO Yianting HU Zhuangqi Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
Proper addition of 0.002 wt-% Mg to cast Fe_3Al alloy may obviously improve the room and high temperature tensile properties.Auger spectra show that Mg segregates near grain boundaries as very thin layers.Observation under TEM reveals that a suitable amount of Mg enhances ability of cooperative internal deformation so that the dislocations will ease the con- tinuous slip deformation through grain boundaries.The fracture feature of Fe_3Al alloy is of transgranular cleavage at room temperature and cracks initiate at grain boundaries.
关键词:
Fe_3Al
,
null
,
null
,
null
LIU Chaosan ZHANG Yongchang SHI Changxu Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China professor
,
Institute of Metal Reserach
,
Academia Sinica
,
Shenyang
,
China
金属学报(英文版)
The melt spun ribbons of Al-La-Y-Ni(Fe)quaternary alloys were prepared by a single- roller melt spinning technique in vacuum.Their amorphous nature,mechanical properties and tensile fracture surface morphology were investigated.The experimental results show that amorphous alloys with high strength and good ductility as well as good thermal stability can be achieved in Al-La-Y-Ni(Fe)system,when the alloy contains 85—90 at.-% Al and less than 10 at.-% La+Y.The maximum tensile fracture strength(σ_f) and microhardness(HV)are as high as 760 MPa and 294 DPN,respectively.The as- quenched ribbons can be bent 180 degree without fracturing.The dominant factors for formation of amorphous Al-La-Y-Ni(Fe)are the strong attractive interaction among Al, La,Y and a decrease of melting temperature.
关键词:
single-roller melt spinning
,
null
,
null
,
null
SUN Chao GUO Jianting TAN Minghui LI Hui WANG Shuhe Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The effects of Cr and Nb on tensile properties at room and elevated temperatures and also on the microstructure have been investigated.An improvement in ductiliy plasicity and the cleavage strength of Fe_3AI may result from adding Cr;the improvement is more pronounced at over 400℃.The formation of Fe_2Nb containing A1 precipitates in the Fe_3AI+Nb alloy provide significant strengthening effect.Additions of Cr and Nb in Fe_3AI can cause a signifi- cant improvement in the yield strength at 550℃.
关键词:
intermetallic compound
,
null
,
null
,
null
,
null
ZHOU Yigang YU Hanqing ZENG Weidong Northwestern Polytechnical University
,
Xi'an
,
ChinaTANG Jialin China South Aviation Motive Power and Machinery Company
,
Zhuzhou
,
China professor
,
Department of Materials Science and Engineering
,
Northwestern Polytechnical University
,
Xi'an 710072
,
China
金属学报(英文版)
Effect of β-flecks on properties of tensile elongation and low cycle.fatigue life at room tern. perature for Ti-10V-2Fe-3Al alloy has been investigated.The cracks along initial β-grain boundaries in the β-fleck region may propagate to form intergranular brittle fracture.Under alternating load,the β-fleck often becomes a fatigue origin.While under higher strain,the cracks initiate and propagate to fracture early at the original β-grain boundaries in β-fleck region and at α-grain boundaries.
关键词:
Ti-10V-2Fe-3Al alloy
,
null
,
null
,
null
CHEN Niug
,
YU Zongsen University of Science and Technology Beijing
,
Beijing
,
China professor
,
Department of Materials Physics
,
University of Science and Technology Beijing
,
Beijing 100083
,
China
金属学报(英文版)
Si segregation was observed in the vacancy condensation pits,formed by supersaturated vacancies beneath the oxidation layer of Al-0.35wt-%Si alloy,by optical microscopy,X- ray photoelectron spectroscopy and microhardness tests.This phenomenon could only be explained by vacancy-Si complex inducing non-equilibrium segregation.
关键词:
non-equilibrium segregation
,
null
,
null
,
null
,
null
ZHOU Diangen CHEN Nianyi Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
China professor
,
Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
200050
,
China
金属学报(英文版)
Pattern recognition method is used for the investigation of stability,region of filled Ti_2Ni phases in multi-dimensional bond-parameter space.The filling of C,N and O atoms into T_6 octahedra consisting of atoms of earhy-transition elements makes the expansion of the stability region of Ti_2Ni phase,and the relative stability of AI_2Cu and MoSi_2 type com- pounds decreases after the introduction of non-metallic elements such as C,N and O.
关键词:
filledTi_2Ni phase
,
null
QU Xuanhui HUANC Baiyun LEI Changming CHEN Shiqi Central South University of Technology
,
Changsha
,
China professor
,
Powder Metallurgy Research Institute
,
Central South University of Technology
,
Changsha 410083
,
China
金属学报(英文版)
Synthesis process of a TiAl+TiB_2 composite from the elemental powders was studied by means of differential scanning calorimetry and X-ray diffractometry.TiB_2 particles may form in TiAl matrix at temperature even below 700℃ owing to the exothermic reactions between Ti and Al powders.TiB_2 particles are very thermally stable,and they almost did not change in their relative amount,morphology and size after the synthesized composite was remelted.In addition,the existence of TiB_2 particles has obvious refining effect in the as-cast microstructure of TiAl-base alloys.
关键词:
TiAl alloy
,
null
,
null
,
null
