TY  - JOUR
T1  - A Study of CaH<SUB>2</SUB> Effectiveness as Oxidation Prevention in Solid State Sintering of Single Phase Niti Alloy
AU - Zaki, Mohd AU - Hanim, Hafizah AU - Abdullah, Jamaluddin 
JO  - Research Journal of Applied Sciences
VL  - 10
IS  - 1
SP  - 28
EP  - 32
PY  - 2015
DA  - 2001/08/19
SN  - 1815-932x
DO  - rjasci.2015.28.32
UR  - https://makhillpublications.co/view-article.php?doi=rjasci.2015.28.32
KW  - martensitic transformation
KW  -shape memory alloys
KW  -Solid state diffusion
KW  -enthalpy change
KW  -Malaysia
AB  - This research aims to study the conditions that may produce single phase NiTi for desirable shape memory effect under solid state by suppressing the oxide levels using CaH<SUB>2</SUB> as in-situ reducing agent. A systematic comparative investigation was made on phase formation and their transformation behavior. Phase formation analysis was carried out using Scanning Electron Microscope (SEM), Energy Dispersive Spectroscope (EDS) and X-Ray Diffractometer (XRD). The transformation behaviour was studied by means of Differential Scanning Calorimetry (DSC) measurements. Thermomechanical analysis was conducted using Thermomechanical Analyzer (TMA). The study revealed that single phase NiTi was successfully formed from Ni-TiH<SUB>2</SUB> specimen sintered at 930&deg;C for 3 h under CaH<SUB>2</SUB> reducing environment with good enthalpy change of &#916;H<SUB>A-M</SUB> = 26 J g<SUP>-1</SUP> and &#916;H<SUB>M-A</SUB> = 25.5 J g<SUP>-1</SUP> upon cooling and heating, respectively. However, the recovery strain reaches 0.75% at maximum 8 N applied load which is still below than the reported bulk NiTi.
ER  -