材料期刊网

IMPROVEMENT OF DUCTILITY AND TOUGHNESS OF Ni-RICH NiAl AT ROOM TEMPERATURE

CHENG Tianyi Beijing Institute of Technology , Beijing , ChinaCANTORB University of Oxford , UKMcLEANM FLOWERHM Imperial College , UK CHENG Tianyi , associate professor , Faculty of Metallography , Beijing Institute of Technology , Beijing 100081 , China

金属学报(英文版)

In rapidly solidified Ni-34.6 at-% Al alloy,when the cooling the rate during solidification reached the order of 10~6 K/s,the size of the microstructures,such as the grains and substructure of the martensite,decreased dramatically.The various kinds of interfaces with high density and homogeneous distribution resisted effectively the propagation of the cracks and resulted in localized plastic deformation ahead of the tips of microcracks.The ductility and toughness at room temperature of the Ni-rich NiAl may be improved considerably.

关键词: NiAl , null , null , null

Identification of Phases in Aluminide Coatings by Means of Interference Layer Metallography

WU Weitao Institute of Corrosion and Protection of Metals , Academia Sinica , Shenyang , China.

材料科学技术（英文）

Interference layer metallography was used to identify the phases present in the aluminide coating on superalloy IN738LC. They are: two intermetallic aluminides NiAl and Ni_3Al, y-solid solution and a Cr-rich solid solution, two sulphides M_(23)C_6 and MC, and two sulphides (Al,Cr)_3S_4 and (Cr,Ti)_3S_4. ZnS and ZnSe are proposed to be vapor deposited onto the surface of the specimen to get good colour contrast and good light-dark contrast. The refractive index and absorption coefficient of all these phases have been detemined.

关键词: coating , null , null , null

METALLOGRAPHY OF TELLURIDE ON FREE CUTTING STEEL

Steel Research

关键词:

Effect of Cooling Start Temperature on Microstructure and Mechanical Properties of X80 High Deformability Pipeline Steel

ZHENG Xiao-fei , KANG Yong-lin , MENG De-liang , AN Shou-yong , XIA Dian-xiu

钢铁研究学报(英文版)

The effect of cooling (laminar cooling) start temperature on the phase constitution was analyzed by quantitative metallography. The martensite/austenite (M/A) island distribution was fixed by colour metallography. The strength and uniform elongation of the steels were tested with quasi-static tensile testing machine. The in-coordinate deformation of the soft and hard phases was analyzed using FEM. The results indicate that when the cooling start temperature is 690 ℃, the mechanical properties are the best, meeting the requirements of X80 high deformability pipeline steel.

关键词: high deformability pipeline steel , cooling start temperature , carbon diffusion , in-coordinate deformation , M/A island

Morphology and Effect of Pre-deformation on Martensites by Colored Metaliography August 24,1990

GUO Yunyi ZHANG Xiumu CAO Honglu Institute of Metal Research , Academia Sinica , Shenyang , 110015 , China.To whom correspondence should be addressed.

材料科学技术（英文）

The colored metallography was used to inves- tigate the morphology of martensite in Fe-Ni-C al- loys.By compression deformation martensite trans- forms from lenticular to thin-plate.It is proved that the bended and broken martensites are inher- ent from compressive predeformation of austenite.

关键词: morphology , null , null

ISOTHERMAL SECTION AT 1000 AND 1100℃ OF Fe-Mn-Al PHASE DIAGRAM

LIU Xingjun HAO Shiming SUN Rongyao Northeast University of Technology , Shenyang , China Department of Materials Science and Engineering , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

Phase equilibria at Fe-Mn side of isothermal section at 1000 and 1100℃ in Fe-Mn- Al system have been determined using the diffusion couple technique and metallography. A three-phase,α+γ+β,region was found at 1000℃.The method of solid/gas diffusion couple used to determine equilibrium phase composition is believed to be feasible for the system containing volatile component.

关键词: Fe-Mn-Al system , null , null

INTERFACIAL ACTIVITY BEHEAVIOR OF FLUX DURING ALUMINIUM BRAZING

ZHANG Qiyun LIU Shuqi LAN Tie FU Yuchuan Peking University , Beijing , China ZHANG Qiyun , Professor , Department of Chemistry , Peking University , Beijing , China

金属学报(英文版)

A study on the interfacial activity behavior of flux during aluminium brazing has been made by using metallography,SEM and electron prob techniques.The results show that the activity, of a flux is caused by the wetting of base metal with the liquid heavy metal reduced from the flux,thus,some regions of liquid alloy created,at which no aluminium oxide film covers on the surfaces.The reduced metal drops are finally trapped in the fillet.The size of the metal drops increases with the decrease of brazing temperature.

关键词: aluminium brazing , null , null

FORMATION OF AUSTENITE SHELL AROUND SPHEROIDAL GRAPHITE AND ITS EFFECT ON DETERIORATION OF GRAPHITE

ZHOU Jiyang Dalian University of Technology , Liaoning , ChinaW.SCHMITZ S.ENGLER Aachen Institute of Technology , FRG Associate Professor , Divisionof Foundry , Dalian Institute of Technology , Liaoning , China

金属学报(英文版)

To study the growth of austenitic shells around the spheroidal graphite,color metallography has been employed.It is found that the shell is not a continuous layer of austenite,but a clus- ter of wedge-shaped crystals.Three types of shells have been observed.That may strongly af- fect the deterioration of the spheroidal graphite.The mechanism of the formation of the austenitic shells has also been discussed.

关键词: Spheroidal graphite , null , null , null

DEFORMATION OF CuZnAl SHAPE MEMORY ALLOYS IN MARTENSITIC STATE

ZHANG Yi Shanghai Institute of Iron and Steel Research , Shanghai , ChinaE.HORNBOGEN Institute for Materials , Ruhr-University Bochum , F.R.G.[Originally published in ACTA METALL SIN(CHINESE EDN)25(3)1989 pp A179—A184.

金属学报(英文版)

Plastic deformation of three CuZnAl shape memory alloys in martensitic state was investi- gated by means of optical and electron metallography,dilatometry and electric resistiviy de- termination.Two of the alloys are in martensitic state at ambient temperature,and the A_f temperature of the third one is far below the ambient temperature.The effect of deformation of alloys in martensitic state on the course and temperature of transformation as well as the hysteresis of transformation cycles has been analyzed and the “effect of the first cycle” has also been discussed.

关键词: shape memory alloy , null , null

Deformation-induced Microstructures of High-Mn Austenite Steel

Qixun DAI Shupeng HUO Jiangsu Institute of Technology , Zhenjiang , 212013 , China

材料科学技术（英文）

Deformation-induced microstructures of high-Mn austenite steel was investigated by metallography,X-ray diffraction and SEM.The ε-martensite and slip-bands are deformation-in- duced on the{111} planes,and appear as thin straight laths with 60～80° alignment difference be- tween them.It was found that ε-martensite and slip bands are kinked at fcc twin boundaries with the kinked angle 35～40°.The bands of equilateral triangle in the microstructure of tensile deformation are presented.

关键词: deformation-induced microstructure , null , null , null , null