TY - JOUR
T1 - The coupling effects of laser thermal shock and surface nitridation on mechanical properties of Zr-based metallic glass
AU - Huang, Hu
AU - Jiang, Minqiang
AU - Yan, Jiwang
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (Grant No. 51705197 , 11522221 ), Opening fund of State Key Laboratory of Nonlinear Mechanics (Grant No. LNM201802 ), Young Elite Scientists Sponsorship Program by CAST (YESS) (Grant No. 2017QNRC001 ), the Fundamental Research Funds for the Central Universities , and Grant-in-Aid for JSPS Fellows (Grant No. 26-04048 ).
PY - 2019/1/5
Y1 - 2019/1/5
N2 - Laser processing is a versatile tool for applications in the field of metallic glasses (MGs). Previous studies reported that surface nitridation, i.e. the formation of ZrN phase, occurred when laser irradiation of Zr-based MG was performed in nitrogen gas. Additionally, it was reported that laser thermal shock usually softened the irradiated surface. Therefore, the coupling effects of laser thermal shock and surface nitridation on mechanical characteristics of Zr-based MG should be further clarified. For this purpose, in this study, laser irradiation of Zr-based MG was conducted under various experimental conditions, followed by evaluating the surface characteristics by X-ray diffraction (XRD), nanoindentation, and energy-dispersive X-ray (EDX) spectroscopy. Experimental results indicated that the nanoindentation hardness, serrated flow, and surface shear bands were significantly affected by laser irradiation in nitrogen gas. Both surface softening and hardening were observed which depended on the experimental conditions. A competition mechanism between laser thermal shock and the introduction of ZrN phase was employed to rationalize these results. Furthermore, the affecting layer of ZrN phase along the depth direction was measured by EDX. The obtained results suggest a new method to introduce secondary phase into Zr-based MG surface and further to tune the mechanical characteristics of MGs.
AB - Laser processing is a versatile tool for applications in the field of metallic glasses (MGs). Previous studies reported that surface nitridation, i.e. the formation of ZrN phase, occurred when laser irradiation of Zr-based MG was performed in nitrogen gas. Additionally, it was reported that laser thermal shock usually softened the irradiated surface. Therefore, the coupling effects of laser thermal shock and surface nitridation on mechanical characteristics of Zr-based MG should be further clarified. For this purpose, in this study, laser irradiation of Zr-based MG was conducted under various experimental conditions, followed by evaluating the surface characteristics by X-ray diffraction (XRD), nanoindentation, and energy-dispersive X-ray (EDX) spectroscopy. Experimental results indicated that the nanoindentation hardness, serrated flow, and surface shear bands were significantly affected by laser irradiation in nitrogen gas. Both surface softening and hardening were observed which depended on the experimental conditions. A competition mechanism between laser thermal shock and the introduction of ZrN phase was employed to rationalize these results. Furthermore, the affecting layer of ZrN phase along the depth direction was measured by EDX. The obtained results suggest a new method to introduce secondary phase into Zr-based MG surface and further to tune the mechanical characteristics of MGs.
KW - Hardness
KW - Laser irradiation
KW - Metallic glass
KW - Serrated flow
KW - Shear band
KW - Surface nitridation
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U2 - 10.1016/j.jallcom.2018.08.195
DO - 10.1016/j.jallcom.2018.08.195
M3 - Article
AN - SCOPUS:85052310804
VL - 770
SP - 864
EP - 874
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -