Vibrational Dynamics of Pd-Ni-P Bulk Metallic Glasses

2021 ◽  
Vol 32 ◽  
Author(s):  
Punit H Suthar ◽  
P N Gajjar

In the present paper, Phonon modes and elastic constant of three different concentrations of PdxNi1-xP (Pd64Ni16P20, Pd40Ni40P20 and Pd16Ni64P20) bulk metallic glass are calculated using (1) Hubbard-Beeby (HB) and (2) Takeno-Goda (TG) approach along with our well established local model potential. The Hartree (H), Farid et al (F) and Sarkar et al (S) local field correlation functions (LFCF) are employed to examine the effect of the screening function on the collective dynamics of Pd-Ni-P bulk metallic glasses. Results are also reported for phonon dispersion curve, propagation elastic wave and elastic properties viz: bulk modulus BT, modulus of rigidity G, Poisson’s ratio ξ, Young’s modulus Y, Debye temperature ƟD. However, the calculated elastic constants results agree well with other theoretical and available experimental data.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2815
Author(s):  
Yu Hang Yang ◽  
Jun Yi ◽  
Na Yang ◽  
Wen Liang ◽  
Hao Ran Huang ◽  
...  

Bulk metallic glasses have application potential in engineering structures due to their exceptional strength and fracture toughness. Their fatigue resistance is very important for the application as well. We report the tension-tension fatigue damage behavior of a Zr61Ti2Cu25Al12 bulk metallic glass, which has the highest fracture toughness among BMGs. The Zr61Ti2Cu25Al12 glass exhibits a tension-tension fatigue endurance limit of 195 MPa, which is higher than that of high-toughness steels. The fracture morphology of the specimens depends on the applied stress amplitude. We found flocks of shear bands, which were perpendicular to the loading direction, on the surface of the fatigue test specimens with stress amplitude higher than the fatigue limit of the glass. The fatigue cracking of the glass initiated from a shear band in a shear band flock. Our work demonstrated that the Zr61Ti2Cu25Al12 glass is a competitive structural material and shed light on improving the fatigue resistance of bulk metallic glasses.


2016 ◽  
Vol 1141 ◽  
pp. 91-95 ◽  
Author(s):  
Payal N. Chauhan ◽  
Chaudhari Prakruti ◽  
R.H. Joshi ◽  
Nisarg K. Bhatt ◽  
Brijmohan Y. Thakore

Different elastic properties of Pd-based Pd64Fe16P20 have been computed using two different forms of pseudopotential. Both the forms differ within the core region suggesting different degrees of orthogonalization and its r-dependence, while outside the core both preserves the Columbic nature. The only parameter, the core radius, separates these regions, and it is calculated using the realistic assumption based on the nearest neighbor distance. Further, five different forms of the local field correlated functions, namely, Hartree (H), Taylor (T), Ichimaru and Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are examined for better understanding regarding the screening effect on different elastic constants for Pd64Fe16P20 bulk metallic glass. The calculated results for the various elastic moduli, Poisson's ratio, sound velocity and phonon dispersion curve are all found to be in general agreement with the available experimental data. This confirms the applicability of the model pseudopotential to bulk metallic systems.


2001 ◽  
Vol 674 ◽  
Author(s):  
M. Chipara ◽  
M. Toacsen ◽  
M. Sorescu

ABSTRACTFerromagnetic resonance data on metallic glasses, at room temperature, in X band, are discussed. The spectra were decomposed into two Lorentzian lines and the angular dependence of their main parameters (line width and position) is fully analyzed. It is proved that the usual approaches are not able to describe accurately the experimental data. This behavior is ascribed to the misalignment of the magnetization with respect to the external magnetic field, and successfully tested by using a “relaxed” resonance condition that allows a small misalignment of the magnetization relative to the external magnetic field.


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