Phase equilibria and phase transformations in the Ti-rich corner of the Fe–Ni–Ti system
While the main features of the Fe-Ni-Ti system are well known at low Ti content, literature review of the Ti-rich corner revealed inconsistencies between experimental reports. This investigation presents new experimental results, defined to remove the uncertainties concerning melting behavior and solid-state phase equilibria of the (Ni,Fe)Ti2 phase with the adjacent (Fe,Ni)Ti (B2, CsCl-type structure) and Beta-Ti (A2, W-type) phases. Six samples have been prepared and examined by differential thermal analysis performed in yttria and alumina crucibles, and by scanning electron microscopy in the as-cast state as well as equilibrated at 900°C.
Thermodynamic Assessment of the Ni-Ti Phase Diagram
A new assessment of the thermodynamic properties of the stable phases of the Ni-Ti system is presented, based on the experimental thermochemical and phase diagram data from the literature. Suitable sublattice models are used to describe the non-stoichiometries of NiTi and Ni 3 Ti. The calculated phase diagram and the thermodynamic properties show good agreement with the experimental information.
17 &mgr;m pixel 640 x 480 microbolometer FPA development at BAE Systems
BAE Systems has developed an advanced 640 x 480 focal plane array (FPA) with a 17 &mgr;m pixel pitch. Sensitivity of ≤ 50 mK was demonstrated and the FPAs were used in imaging demonstrations. Successful scaling of BAE Systems' patented single contact per pixel, single-level microbolometer process to 17 &mgr;m pitch provides a path toward next generation microbolometer imaging systems.