Crystallization in Al 88 RE 8 Ni 4 glass-forming alloys

2002 ◽  
Vol 82 (12) ◽  
pp. 2483-2497 ◽  
Author(s):  
T. K. Croat ◽  
A. K. Gangopadhyay ◽  
K. F. K Elton
Keyword(s):  
Author(s):  
Gareth Thomas

Silicon nitride and silicon nitride based-ceramics are now well known for their potential as hightemperature structural materials, e.g. in engines. However, as is the case for many ceramics, in order to produce a dense product, sintering additives are utilized which allow liquid-phase sintering to occur; but upon cooling from the sintering temperature residual intergranular phases are formed which can be deleterious to high-temperature strength and oxidation resistance, especially if these phases are nonviscous glasses. Many oxide sintering additives have been utilized in processing attempts world-wide to produce dense creep resistant components using Si3N4 but the problem of controlling intergranular phases requires an understanding of the glass forming and subsequent glass-crystalline transformations that can occur at the grain boundaries.


Author(s):  
Matthew R. Libera ◽  
Martin Chen

Phase-change erasable optical storage is based on the ability to switch a micron-sized region of a thin film between the crystalline and amorphous states using a diffraction-limited laser as a heat source. A bit of information can be represented as an amorphous spot on a crystalline background, and the two states can be optically identified by their different reflectivities. In a typical multilayer thin-film structure the active (storage) layer is sandwiched between one or more dielectric layers. The dielectric layers provide physical containment and act as a heat sink. A viable phase-change medium must be able to quench to the glassy phase after melting, and this requires proper tailoring of the thermal properties of the multilayer film. The present research studies one particular multilayer structure and shows the effect of an additional aluminum layer on the glass-forming ability.


1997 ◽  
Vol 7 (11) ◽  
pp. 1635-1650 ◽  
Author(s):  
A. Faivre ◽  
L. David ◽  
J. Perez

Alloy Digest ◽  
2011 ◽  
Vol 60 (4) ◽  

Abstract DELORO 15, 21, 22, and 25 are prealloyed, gas-atomized, nickel-base powders for repair of glass-forming molds. This datasheet provides information on composition, physical properties, and hardness. It also includes information on powder metal forms. Filing Code: Ni-689. Producer or source: Stellite Coatings.


2011 ◽  
Author(s):  
Ditte Gundermann ◽  
Ulf R. Pedersen ◽  
Tina Hecksher ◽  
Nicholas P. Bailey ◽  
Bo Jakobsen ◽  
...  

1991 ◽  
Vol 56 (10) ◽  
pp. 2142-2147
Author(s):  
Ivo Sláma

The dependence of the induction period of crystallization on supercooling was examined for the silver nitrate-ethylene glycol system over the concentration region of silver nitrate lome fraction of 0 to 0.12. Addition of AgNO3 to ethylene glycol was found to increase considerably the critical induction period of crystallization, although to a lesser extent than Ca(NO3)2, CaCl2, ZnCl2, LiCl and LiNO3 do. The effect of these salts on the critical induction period of crystallization in dimethylsulfoxide, dimethylformamide, dimethylacetamide and methanol was compared in terms of the solvent-rich composition limit of the glass-forming ability. By using the TTT(Time-Temperature-Transformation) theory, it has been deduced that the effect of the salts on the critical induction period of crystallization of ethylene glycol is probably due to the different dependences of viscosity on their concentration in ethylene glyco in the supercooling region.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 954
Author(s):  
Xavier Monnier ◽  
Sara Marina ◽  
Xabier Lopez de Pariza ◽  
Haritz Sardón ◽  
Jaime Martin ◽  
...  

The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.


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