Elastic constants and martensitic phase transitions in FePt and FeNiPt invar alloys

✍ Scribed by U. Kawald; W. Zemke; H. Bach; J. Pelzl; G.A. Saunders

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 245 KB
• Volume: 161
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(89)90106-3

✦ Synopsis

The single crystal elastic constants of the invar alloys Fe,,Pt,,, Fe,,Pt,, and Fe,,Ni,Ptz, have been investigated by the ultrasonic pulse echo technique in the temperature range 4-330 K. The temperature dependence of the elastic constants in the partially ordered alloy Fe,,Pt,, resembles the behaviour reported in previous studies. In Fe,,Ptzs and in Fe,ZNiqPtz, the ultrasonic echoes of the longitudinal modes disappear at 205 and 170 K, respectively. At the same temperatures the shear elastic constant C' becomes zero for both alloys. A hysteresis of about 50 K supports the martensitic nature of this first order transition.