|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Mechanical Behavior at the Nanoscale III
||W-21: Spherical Indentation Response of Ti64, Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 Shape Memory Alloys at Elevated Temperature
||Peizhen Li, Haluk E Karaca, Yang-Tse Cheng
|On-Site Speaker (Planned)
Indentation techniques can be used to investigate the shape memory alloys (SMAs) at nano- and micro-meter length scales. In this presentation, we report the spherical indentation responses of Ti-6Al-4V, Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 alloys up to 340 °C. Differential Scanning Calorimetry (DSC) results revealed that both Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 are martensitic at room temperature and they transform to austenite upon heating. Moreover, Ni50.3Ti29.7Hf20 has higher hardness, strength and transformation temperatures but lower transformation strain than Ni49.9Ti50.1. Ti-6Al-4V does not undergo phase transformation and it is selected for comparison. A spherical indenter with r= 25 µm was used to indent the samples at selected load levels. The change in hardness, modulus and recovery ratios are determined as functions of temperature and maximum indentation load. Experimental results showed that indentation hardness of Ti-6Al-4V decreases with temperature, while hardness of Ni49.9Ti50.1 and Ni50.3Ti29.7Hf20 shows a complicated change with temperature due to phase transformation.
||Planned: A print-only volume