Effect of Heat Treatments on Morphology and Transformation Temperatures of Sputtered Ti-Ni Thin Films

Autor: Yoshiyuki Nakata, Ken’ichi Shimizu, A. Tanaka, T. Tadaki
Rok vydání: 1995
Předmět:
Zdroj: Journal de Physique IV. :C8-671
ISSN: 1155-4339
DOI: 10.1051/jp4/199558671
Popis: Morphology and martensitic transformation temperatures of sputter-deposited Ti 51.5 Ni 48.5 thin films were investigated by carrying out transmission electron microscopy (TEM) of those films before and after annealing at several different temperatures. The thin films were prepared by RF magnetron sputtering. TEM observations showed that the as-deposited thin films were all amorphous and contained no crystalline phases even after annealing at lower temperatures than 370°C. However, they were crystallized into a B2 type order phase by annealing at higher temperatures than 400°C. The grain size was about 1-2 μm and not sensitive to annealing temperature. Subgrain boundaries and plate-shaped defects were observed in the specimens annealed at 400°C and 500°C, respectively, and Ti 2 Ni precipitates were in the specimen annealed at higher temperatures than 600°C. M s temperature for the B2 → B19' martensite transformation decreases with decreasing annealing temperature. On the contrast to M s , T R temperature for the B2 → R phase transformation was hardly affected by annealing temperature.
Databáze: OpenAIRE