An Estimation of Enthalpy of Amorphous Alloys using Differential Thermal Analysis (DTA) Technique

The enthalpy energies are calculated   by using   exothermic peaks of differential (thermal analysis (DTA) en Cobalt-Boron liquid quenched amorphous alloys. The endothermic peaks are not distinctly recorded.   The  diffusional  recovery  processes  in Co-B  LQA   alloys occur  at  about  693K  and  temperatures less    than 800K;  which  suggests  that the polymorphic transformation of   cobalt   is   responsible   for   diverse   diffusion  recovery    processes   such  as intestinal and   vacancy formations,   Cottrell-Lomer locks,  point  defects  due   to  free  covalent bonds (dangling   bonds), edge/edge    and  screw/screw   annihilations through forced  climb  due  to   thermal  stresses  and  indeed   due   to   non-operative  slip   systems  of  cobalt   (both  basal   and pyramidal slips).   Structural changes  in  Co-B  LQA alloys   occur  at above  800K mainly  due  to operative slip systems  in  Cobalt (both  basal  and pyramidal)  which  cross   each other (cross-slip) due  to  thermal  stresses  and annealing.  The cross-slip in  o p.h.  metals (cobalt) particularly  allow temperatures is indeed difficult.

A HUSSIAN ,S M RAZA ,S M M R NAQVI ,S D H RIZVI ,S RIZVI ,F REHMAN ,