Peipei Lu, Meiping Wu, Xin Liu, Xiaojin Miao and Weipeng Duan
Ti6Al4V is a widely used metal for biomedical application due to its excellent corrosion resistance, biocompatibility and mechanical strength. However, a coupling reaction of…
Abstract
Purpose
Ti6Al4V is a widely used metal for biomedical application due to its excellent corrosion resistance, biocompatibility and mechanical strength. However, a coupling reaction of friction and corrosion is the critical reason for the failure of implants during the long-term service in human body, shortening the life expectancy and clinical efficacy of prosthesis. Hence, this study aims to find a feasible approach to modify the service performances of Ti6Al4V.
Design/methodology/approach
Selective laser melting (SLM), as one of the emerging metal-based additive manufacturing (AM) technologies is capable for fabricating patient-specific personalized customization of artificial prosthesis joints, owing to its high adaptability for complex structures. This study is concerned with the tribocorrosion behavior of SLM fabricated Ti6Al4V substrate enhanced by laser rescanning and graphene oxide (GO) mixing. The tribocorrosion tests were performed on a ball-on-plate configuration under the medium of simulated body fluid (SBF). Moreover, the surface morphologies, microstructures, microhardness and contact angle tests were used to further reveal the in-situ strengthening mechanism of GO/Ti6Al4V nanocomposites.
Findings
The results suggest that the strengthening method of GO mixing and laser rescanning shows its capability to enhance the wear resistance of Ti6Al4V by improving surface morphologies and promoting the generation of hard phases. The wear volume of R-GO/Ti6Al4V is 5.1 × 10−2 mm3, which is 25.0% lower than that of pure SLM-produced Ti6Al4V. Moreover, a wear-accelerated corrosion of the Ti6Al4V occurs in SBF medium, leading to a drop in the open circuit potential (OCP), but R-GO/Ti6Al4V has the lowest tendency to corrosion. Compared to that of pure Ti6Al4V, the microhardness and contact angle of R-GO/Ti6Al4V were increased by 32.89% and 32.60%, respectively.
Originality/value
Previous investigations related to SLM of Ti6Al4V have focused on improving its density, friction and mechanical performances by process optimization or mixing reinforcement phase. The authors innovatively found that the combination of laser rescanning and GO mixing can synergistically enhance the tribocorrosion properties of titanium alloy, which is a feasible way to prolong the service lives of medical implants.
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Weipeng Duan, Jitai Han, Qingfneg Xia, Keqing Wang, Meiping Wu and Dalei Song
With the increasing demand for lightweight parts, the quality of the inner structure gained growing attention from different kinds of fields. As the quality of the overhanging…
Abstract
Purpose
With the increasing demand for lightweight parts, the quality of the inner structure gained growing attention from different kinds of fields. As the quality of the overhanging surface was one of the most important factors affecting inner structure formation, its quality still needs to improve. This paper aims to clarify the change of the overhanging surface quality caused by different bending angles.
Design/methodology/approach
The structure of the inner hole was redesigned according to the different performances of the overhanging and side inner surface. The experimental results revealed why different surface qualities can be seen under different bending angles. According to the experimental data, the inner structure was redesigned to increase its overall performance.
Findings
The results revealed that when the bending angle was small, the slope of the overhanging surface increased which lead to the decreasing length of the powder-supported layer. However, less space on bending angle resulted in the accumulation of unmelted powder which leads to the increasing of sinking distance. When the bending angle was too large, the slope of the overhanging surface decreased and the length of the molten pool which was supported by powder increased. It resulted in the sinking of the molten pool caused by the gravity of powder and its attachment.
Originality/value
This paper is the first work to study the relationship between bending angle and overhanging surface quality as far as the authors know. The different performances of left and right overhanging surfaces also have not been revealed in other research studies to the best of the knowledge.
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Yuan Liang, Tung-Ju Wu and Weipeng Lin
Most employees are forced to telework due to the COVID-19 pandemic, which brings novel, disruptive, and critical challenges both in work and life. Based on event system theory and…
Abstract
Purpose
Most employees are forced to telework due to the COVID-19 pandemic, which brings novel, disruptive, and critical challenges both in work and life. Based on event system theory and equity theory, this research explores how and when forced teleworking event strength (i.e. novelty, disruption, and criticality) affects employees’ work and life-related outcomes.
Design/methodology/approach
We conducted two studies to test the hypothesized moderated mediation model (Study 1: an experiment survey, N = 141; Study 2: a time-lagged survey, N = 243) with employees forced to telework from China.
Findings
The results largely support our hypotheses. Study 1 indicates that the manipulation of forced teleworking event strength (high vs low) is effective, and the main effect of forced teleworking event strength on work-family conflict is significant. Moreover, Study 2 shows that work-family conflict mediates the relationship between forced teleworking event strength (i.e. novelty, disruption, and criticality) and counterproductive work behavior (CWB). Furthermore, perceived overqualification positively moderates the relationship between work-family conflict and CWB. In detail, the relationship between work-family conflict and CWB becomes stronger when perceived overqualification is higher.
Originality/value
This research provides a new perspective on how forced teleworking event strength impacts CWB and advances the literature on the relevant theories.