Lattice Expansion and Ge Solubility in the Ag1-?Ge? Terminal Solid Solution

2002 ◽  
Vol 234 (2) ◽  
pp. 496-505 ◽  
Author(s):  
A. Filipponi ◽  
V.M. Giordano ◽  
M. Malvestuto
Calphad ◽  
1979 ◽  
Vol 3 (2) ◽  
pp. 109-118 ◽  
Author(s):  
S.S. Balakrishna ◽  
A.K. Mallik

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Tian Wang ◽  
Dmytro Kevorkov ◽  
Ahmad Mostafa ◽  
Mamoun Medraj

Al-Mn-Zn ternary system is experimentally investigated at 400°C using diffusion couples and key alloys. Phase relationships and homogeneity ranges are determined for binary and ternary compounds using EPMA, SEM/EDS, and XRD. Reported ternary compound T3 (Al11Mn3Zn2) is confirmed in this study and is denoted as τ2 in this paper. Two new ternary compounds (τ1 and τ3) are observed in this system at 400°C. τ1 is determined as a stoichiometric compound with the composition of Al31Mn8Zn11. τ3 has been found to have homogeneity range of AlxMnyZnz (x=9–13 at%; y=11–15 at%; z=75–77 at%). The binary compounds Al4Mn and Al11Mn4 exhibit limited solid solubility of around 6 at% and 4 at% Zn, respectively. Terminal solid solution Al8Mn5 is found to have maximum ternary solubility of about 10 at% Zn. In addition, ternary solubility of Al-rich β-Mn′ at 400°C is determined as 4 at% Zn. Zn-rich β-Mn′′ has a ternary solubility of 3 at% Al. The solubility of Al in Mn5Zn21 is measured as 5 at%. Based on the current experimental results, the isothermal section of Al-Mn-Zn ternary system at 400°C has been constructed.


1981 ◽  
Vol 10 ◽  
Author(s):  
Xian-Fu Zeng ◽  
D. D. L. Chung

The solid state interfacial reaction between gold and GaAs, was found to result in small surface microstructural changes, whereas melting of the reaction product (tentatively identified as AuGa) and subsequent solidification to form the β phase resulted in aligned rectangular protrusions with sharp corners. The rectangular protrusions were found to be much finer in scale after heating in a vacuum than after heating in argon at 1 atm. High cooling rates (e.g. 40°C min−1) during solidification resulted in the formation of both rectangular protrusions and irregularly shaped protrusions with jagged boundaries and topography. The irregular protrusions were associated with a phase tentatively identified as Au2Ga. Rapid cooling at about 600°C min−1 during solidification resulted in the formation of the gold-rich terminal solid solution (α phase) which appeared as aligned rectangular protrusions with rounded corners.


2000 ◽  
Vol 646 ◽  
Author(s):  
Satoshi Semboshi ◽  
Naoya Masahashi ◽  
Shuji Hanada

ABSTRACTPulverization behavior and microstructure evolution with hydrogenation in hydrogen absorbing Ta-Ni intermetallic-based alloys, such as Ta2Ni with Ta solid solution (Tass), TiMn2 with TiMn and Nb3Al with Nb solid solution (Nbss), are investigated to elucidate the mechanism of the hydrogen pulverization. Ta-10at.%Ni consisting of Ta solid solution (Tass) and Ta2Ni Laves phase is pulverized to coarse powder over 100 μm in hydrogenation. Crack propagation occurs preferentially in the brittle Ta2Ni phase rather than in the ductile Tass phase. When the volume fraction of brittle Ta2Ni increases with increasing Ni content, hydrogen pulverization is enhanced. The lattice parameter of Tass increases by hydrogenation, while it does not change in Ta2Ni. In addition, nano-sized regions with Moiré patterns are produced in Tass and Debye rings corresponding to tantalum hydride β-TaH appear in the diffraction pattern. These features are very similar to those of TiMn2 based alloy and Nb3 Al based alloys in the literature. Based on the present results along with those in the literature it is concluded that the hydrogen pulverization is attributable to (1) the absorption of a large amount of hydrogen in constituent phase(s), (2) the large strain introduced by lattice expansion and the hydride formation, and (3) the ease of crack nucleation and propagation in brittle constituent phase(s).


Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.


Author(s):  
A. Christou ◽  
J. V. Foltz ◽  
N. Brown

In general, all BCC transition metals have been observed to twin under appropriate conditions. At the present time various experimental reports of solid solution effects on BCC metals have been made. Indications are that solid solution effects are important in the formation of twins. The formation of twins in metals and alloys may be explained in terms of dislocation mechanisms. It has been suggested that twins are nucleated by the achievement of local stress-concentration of the order of 15 to 45 times the applied stress. Prietner and Leslie have found that twins in BCC metals are nucleated at intersections of (110) and (112) or (112) and (112) type of planes.In this paper, observations are reported of a transmission microscope study of the iron manganese series under conditions in which twins both were and were not formed. High strain rates produced by shock loading provided the appropriate deformation conditions. The workhardening mechanisms of one alloy (Fe - 7.37 wt% Mn) were studied in detail.


Author(s):  
Jordi Marti ◽  
Timothy E. Howson ◽  
David Kratz ◽  
John K. Tien

The previous paper briefly described the fine microstructure of a mechanically alloyed oxide dispersion strengthened nickel-base solid solution. This note examines the fine microstructure of another mechanically alloyed system. This alloy differs from the one described previously in that it is more generously endowed with coherent precipitate γ forming elements A1 and Ti and it contains a higher volume fraction of the finely dispersed Y2O3 oxide. An interesting question to answer in the comparative study of the creep and stress rupture of these two ODS systems is the role of the precipitate γ' in the mechanisms of creep and stress rupture in alloys already containing oxide dispersoids.The nominal chemical composition of this alloy is Ni - 20%Cr - 2.5%Ti - 1.5% A1 - 1.3%Y203 by weight. The system receives a three stage heat treatment-- the first designed to produce a coarse grain structure similar to the solid solution alloy but with a smaller grain aspect ratio of about ten.


Author(s):  
R. M. Anderson

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.


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