Effects of Test Temperature and Loading Conditions on the Tensile Properties of a Zr-Based Bulk Metallic Glass |
| |
| Authors: | A.H. Vormelker O.L. Vatamanu L. Kecskes J.J. Lewandowski |
| |
| Affiliation: | (1) Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA;(2) Present address: Marine Mechanical Corporation, 24703 Euclid Avenue, Cleveland, OH 44117, USA;(3) Case Western Reserve University, Cleveland, OH 44106, USA;(4) Present address: Powdermet, Inc, Euclid, OH 44117, USA;(5) U.S. Army Research Laboratory, Aberdeen Proving Ground, MD 21005-5069, USA |
| |
| Abstract: | The effects of changes in test temperature (20 °C, 260 °C, 330 °C, and 380 °C), strain rate (10−5 to 10−1 s−1), and loading conditions (displacement control vs loading-rate control) on the tensile behavior of Zr41.2Ti13.8Cu12.5Ni10Be22.5 (LiquidMetal 1 (LM1)), a bulk metallic glass (BMG), have been determined. Significant effects of the test temperature, strain rate, and loading condition were observed on the strength, ductility/elongation, and mechanisms of failure (shear, ductile rupture, etc.). This material exhibited extensive elongation (i.e., >100 pct) prior to failure when tested near the glass transition temperature (T g ≈ 375 °C) at sufficiently low strain rates, while higher strain rates or lower test temperatures produced shear fracture at low elongation. The flow and fracture behavior was also significantly affected by the loading condition (i.e., displacement vs loading-rate control). The effective strain rate necessary to cause failure in shear without significant global flow was several orders of magnitude lower in loading-rate control than in displacement control. Samples exhibiting high elongation tested in displacement control gently and convexly drew to a near point (i.e., ductile rupture). Samples tested at the same temperature exhibiting high elongation in loading-rate control rapidly and concavely necked, followed by drawing to a constant diameter “wire” (i.e., ductile drawing), eventually failing by nearly pure ductile rupture. All samples that displayed significant elongation did so inhomogeneously, and were characterized by non-Newtonian global flow. This article is based on a presentation given in the symposium entitled “Bulk Metallic Glasses IV,” which occurred February 25–March 1, 2007 during the TMS Annual Meeting in Orlando, Florida under the auspices of the TMS/ASM Mechanical Behavior of Materials Committee.
|
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
