Chemical Compatibility of High Temperature Intermetallic Compounds with Various Potential Reinforcements

1990 ◽  
Vol 194 ◽  
Author(s):  
J.-M. Yang ◽  
S. M. Jeng ◽  
C. J. Yang ◽  
D. L. Anton

AbstractThe chemical compatibility between five high temperature intermetallic compounds and six potential reinforcements are investigated. Diffusion couples are prepared by vacuum hot pressing. The most promising reinforcements or coating for each intermetallic compound are identified.

1990 ◽  
Vol 213 ◽  
Author(s):  
C. Steve Chang ◽  
D. P. Pope

AbstractHigh temperature compression tests were performed on Cr 3Si single crystalline and poly crystalline samples. Slip systems were determined to be of the {001}<010> type based on an analysis of slip traces and Laue spots. Single crystals show significant compressive ductility at temperatures above 0.7Tm. The implication of cube slip on the ductility of A15-type intermetallic compounds is discussed.


Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1967
Author(s):  
Qiong Wan ◽  
Fuguo Li ◽  
Wenjing Wang ◽  
Junhua Hou ◽  
Wanyue Cui ◽  
...  

In this study, ball-milled powder of Ti and Al was used to fabricate Ti–Al intermetallic compound-reinforced Al matrix composites by an in-situ reaction in cold-pressing sintering and hot-pressing sintering processes. The detailed microstructure of the Ti–Al intermetallic compound-reinforced Al composite was characterized by optical microscopy (OM), X-ray diffraction (XRD), energy dispersive spectrometry (EDS), and electron backscattered diffraction (EBSD). The results indicate that a typical core–shell-like structure forms in the reinforced particles. The shell is composed of a series of Ti–Al intermetallic compounds and has good bonding strength and compatibility with the Al matrix and Ti core. With cold-pressing sintering, the shell around the Ti core is closed, and the shell thickness increases as the milling time and holding time increase. With hot-pressing sintering, some radiating cracks emerge in the shell structure and provide paths for further diffusion of Ti and Al atoms. The Kirkendall effect, which is caused by the difference between the diffusion coefficients of Ti and Al, results in the formation of cavities and a reduction in density degree. When the quantity of the intermetallic compounds increases, the hardness of the composites increases and the plasticity decreases. Therefore, factors that affect the quantity of the reinforcements, such as the milling time and holding time, should be determined carefully to improve the comprehensive properties of the composites.


2004 ◽  
Vol 37 (2) ◽  
pp. 339-340 ◽  
Author(s):  
S. F. Treviño ◽  
D. F. R. Mildner

The method and parameters for vacuum hot pressing of single-crystal germanium, suitable for a large-area double-focusing neutron monochromator, are presented. The square virgin crystals have a mosaic that is less than 0.01° and isotropic. After appropriate pressing at high temperature (1073 K at a pressure of 10.7 MPa) the mosaic becomes anisotropic, about 0.5° in one direction and 0.2° in the other. The distribution of the mosaic widths of the crystals in the two directions are given, together with their composite values.


2007 ◽  
Vol 345-346 ◽  
pp. 653-656 ◽  
Author(s):  
Hyeon Taek Son ◽  
Jae Seol Lee ◽  
Ji Min Hong ◽  
Ik Hyun Oh ◽  
Kyosuke Yoshimi ◽  
...  

The aims of this research are to investigate the effect of Sm addition in Mg-Al-Ca alloys on microstructure and mechanical properties. Sm addition to Mg-5Al-3Ca based alloys results in the change from dendritic to equiaxed grain morphorlogy and formation of Al-Sm rich itermetallic compounds at grain boundary and α-Mg matrix. And these Al-Sm rich intermetallic compounds were dispersed homogeously and stabilized at high temperature. And maximum yield and ultimate strength value was obtained at Mg-5Al-3Ca-2Sm alloys at elevated temperature because of homogeneous dispersion of stable Al-Sm rich intermetallic compound at high temperature.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1562
Author(s):  
Chao Ding ◽  
Jian Wang ◽  
Tianhan Liu ◽  
Hongbo Qin ◽  
Daoguo Yang ◽  
...  

Full intermetallic compound (IMC) solder joints present fascinating advantages in high-temperature applications. In this study, the mechanical properties and elastic anisotropy of η’-Cu6Sn5 and Cu3Sn intermetallic compounds were investigated using first-principles calculations. The values of single-crystal elastic constants, the elastic (E), shear (G), and bulk (B) moduli, and Poisson’s ratio (ν) were identified. In addition, the two values of G/B and ν indicated that the two IMCs were ductile materials. The elastic anisotropy of η’-Cu6Sn5 was found to be higher than Cu3Sn by calculating the universal anisotropic index. Furthermore, an interesting discovery was that the above two types of monocrystalline IMC exhibited mechanical anisotropic behavior. Specifically, the anisotropic degree of E and B complied with the following relationship: η’-Cu6Sn5 > Cu3Sn; however, the relationship was Cu3Sn > η’-Cu6Sn5 for the G. It is noted that the anisotropic degree of E and G was similar for the two IMCs. In addition, the anisotropy of the B was higher than the G and E, respectively, for η’-Cu6Sn5; however, in the case of Cu3Sn, the anisotropic degree of B, G, and E was similar.


1994 ◽  
Vol 364 ◽  
Author(s):  
Yukinori Ikarashi ◽  
K. Ishizaki ◽  
P. Bolsaitis ◽  
H. Ohnishi

AbstractThe zirconium silicide intermetallic compounds of 16H crystal structure are good materials for high temperature structural applications because of their high melting point and low density. Their shortcoming is low ductility. To increase ductility, new ternary zirconium silicide intermetallic compound of 16H crystal structure, Si3Y3Zr2, has been designed by substituting yttrium atoms into zirconium 6g point set sites.Near-neighbor diagrams are used to examine the bonds in Si3Y3Zr2, whose bonds are more symmetric than other 16H binary intermetallic compounds.Melting points of intermetallic compounds of 16H crystal structure depend upon the strain parameters of N4d-N4d(2-2) bonds. The melting point of Si3Y3Zr2 is estimated to be higher than that of Si3Zr5 (2500 K). It is predicted that Si3Y3Zr2 is a good material for high temperature structural applications.


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