T.W. Zhang

Tribological Properties of AlCrCuFeNi2 High-Entropy Alloy in Different Conditions

In order to understand the environmental effect on the mechanical behavior of high-entropy alloys, the tribological properties of AlCrCuFeNi2 are studied systematically in dry, simulated rainwater, and deionized water conditions against the Si3N4 ceramic ball at a series of different normal loads. The present study shows that both the friction and wear rate in simulated rainwater are the lowest. The simulated rainwater plays a significant role in the tribological behavior with the effect of forming passive film, lubricating, cooling, cleaning, and corrosion. The wear mechanism in simulated rainwater is mainly adhesive wear accompanied by abrasive wear as well as corrosive wear. In contrast, those in dry condition and deionized water are abrasive wear, adhesive wear, and surface plastic deformation. Oxidation contributes to the wear behavior in dry condition but is prevented in liquid condition. In addition, the phase diagram of AlxCrCuFeNi2 is predicted using CALPHAD modeling, which is in good agreement with the literature report and the present study.

Erratum to: Tribological Properties of AlCrCuFeNi2 High-Entropy Alloy in Different Conditions

YONG LIU and TENG ZHANG, Graduate Students, and HUIJUN YANG, Associate Professor, are with the Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China, and also with the College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China. Contact e-mail: pineyang@126.com SHENGGUO MA, Lecturer and ZHIHUA WANG, Professor, are with the Institute of Applied Mechanics and Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P.R. China. MICHAEL C. GAO, Principal Materials Scientist, is with National Energy Technology Laboratory, 1450 Queen Ave SW, Albany, OR 97321, and also with AECOM, P.O. Box 1959, Albany, OR. CHUAN ZHANG, Materials Scientist, is with CompuTherm LLC, 437 S. Yellowstone Dr., Suite 217, Madison, WI, 53719. JUNWEI QIAO, Professor, is with the College of Materials Science and Engineering, Taiyuan University of Technology. Contact e-mail: qiaojunwei@gmail.com The online version of the original article can be found under doi:10.1007/s11661-016-3396-8. Article published online March 9, 2016

Tribological Properties of a Dendrite-reinforced Ti-based Metallic Glass Matrix Composite under Different Conditions

The tribological properties of the in-situ dendrite-reinforced metallic glass matrix composite (Ti42 Zr32 V14–Cu5 Be17) prepared by copper mould casting were analyzed at different normal loads under the dry condition and rainwater. The results showed that the average value of the frictional coefficients and micro-hardness ascended with increasing the normal load, while the wear rate showed a trend of decline under the dry condition. The electrochemical test results showed that the surface of samples was pitting corroded in the rainwater. The matrices were corroded first. Then the dendrites were exposed, leading to the damage of the surface. Both the frictional coefficients and wear rate of the composite in the rainwater were larger than those under the dry condition, primarily owing to the corrosion of chloride ions on the worn surface. The wear mechanisms of composites were mainly adhesive wear, accompanied by the abrasive wear under the dry condition and corrosive wear in the rainwater. The composites have higher wear resistance both under the dry condition and rainwater due to the lower wear rate.

Dynamic Deformation Behaviors of an In Situ Ti-Based Metallic Glass Matrix Composite

Quasi-static and dynamic deformation behaviors, fracture characteristics, and microstructural evolution of an in situ dendrite-reinforced metallic glass matrix composite: Ti50Zr20V10Cu5Be15 within a wide range of strain rates are investigated. Compared with the quasi-static compression, the yielding stress increases, but the macroscopic plasticity significantly decreases upon dynamic compression. The effects of the strain rate on strain hardening upon quasi-static loading and flow stress upon dynamic loading are evaluated, respectively. The Zerilli-Armstrong (Z-A) model based on dendrite-dominated mechanism is employed to further uncover the dependence of the yielding stress on the strain rate.