TY - JOUR
T1 - A Comparative Study of Local Heat Treatment for Enhancing Overall Mechanical Properties of Clinched Joints
AU - Liu, Fulong
AU - He, Xiaocong
AU - Gu, Fengshou
AU - Ball, Andrew D.
N1 - Funding Information:
The author would like to thank the National Science Foundation of China (Grant No. 51565023) for the sponsorship to carry out the research. The experimental materials and facilities were provided by Kunming University of Science and Technology, Kunming, PRC.
Publisher Copyright:
© 2021, ASM International.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/2/1
Y1 - 2021/2/1
N2 - Clinching technology is widely used for joining lightweight materials. It is well known that the fatigue life of clinched joints is outstanding, but its static strength is inferior to other conventional joints such as resistance spot welding joints. In this study, a post-processing method was proposed to enhance the overall mechanical performances of clinched joints in material of steel plate cold commercial steel. Based on the failure mechanism analysis, we performed quenching, a local heat treatment process, on the joining zone to improve the static strength of clinched joints. The static strength and fatigue life of clinched joints before and after quenching were compared via experimental study. The experimental results showed that the tensile–shearing strength of clinched joint increased by 60.65% and the fatigue life was extended when the joint was under high fatigue load levels after local heat treatment. Besides, metallographic test and fracture analysis were conducted to analyze the mechanism of the change of mechanical behaviors. Lath martensite was observed in the cross section of clinched joint after local heat treatment, which is the main reason for the tensile–shearing strength increase as martensite has higher strength than ferrite and pearlite. The fracture analysis showed that the fatigue fracture mode became transcrystalline rupture after local heat treatment when the clinched joint was under low fatigue load levels, which lead to the fatigue behavior of clinched joints weakened. Nonetheless, the overall mechanical properties of clinched joints were improved.
AB - Clinching technology is widely used for joining lightweight materials. It is well known that the fatigue life of clinched joints is outstanding, but its static strength is inferior to other conventional joints such as resistance spot welding joints. In this study, a post-processing method was proposed to enhance the overall mechanical performances of clinched joints in material of steel plate cold commercial steel. Based on the failure mechanism analysis, we performed quenching, a local heat treatment process, on the joining zone to improve the static strength of clinched joints. The static strength and fatigue life of clinched joints before and after quenching were compared via experimental study. The experimental results showed that the tensile–shearing strength of clinched joint increased by 60.65% and the fatigue life was extended when the joint was under high fatigue load levels after local heat treatment. Besides, metallographic test and fracture analysis were conducted to analyze the mechanism of the change of mechanical behaviors. Lath martensite was observed in the cross section of clinched joint after local heat treatment, which is the main reason for the tensile–shearing strength increase as martensite has higher strength than ferrite and pearlite. The fracture analysis showed that the fatigue fracture mode became transcrystalline rupture after local heat treatment when the clinched joint was under low fatigue load levels, which lead to the fatigue behavior of clinched joints weakened. Nonetheless, the overall mechanical properties of clinched joints were improved.
KW - clinched joints
KW - fatigue
KW - local heat treatment
KW - mechanical properties
KW - tensile–shearing
UR - http://www.scopus.com/inward/record.url?scp=85099222356&partnerID=8YFLogxK
U2 - 10.1007/s11665-020-05446-w
DO - 10.1007/s11665-020-05446-w
M3 - Article
AN - SCOPUS:85099222356
VL - 30
SP - 1347
EP - 1355
JO - Journal of Materials Engineering and Performance
JF - Journal of Materials Engineering and Performance
SN - 1059-9495
IS - 2
ER -
