RESUMEN
Clarifying the deformation behaviors of microstructures could greatly help us understand the precipitation-strengthening mechanism in alloys. However, it is still a formidable challenge to study the slow plastic deformation of alloys at the atomic scale. In this work, the phase-field crystal method was used to investigate the interactions between precipitates, grain boundary, and dislocation during the deformation processes at different degrees of lattice misfits and strain rates. The results demonstrate that the pinning effect of precipitates becomes increasingly strong with the increase of lattice misfit at relatively slow deformation with a strain rate of 10-4. The cut regimen prevails under the interaction between coherent precipitates and dislocations. In the case of a large lattice misfit of 19.3%, the dislocations tend to move toward the incoherent phase interface and are absorbed. The deformation behavior of the precipitate-matrix phase interface was also investigated. Collaborative deformation is observed in coherent and semi-coherent interfaces, while incoherent precipitate deforms independently of the matrix grains. The faster deformations (strain rate is 10-2) with different lattice misfits all are characterized by the generation of a large number of dislocations and vacancies. The results contribute to important insights into the fundamental issue about how the microstructures of precipitation-strengthening alloys deform collaboratively or independently under different lattice misfits and deformation rates.
RESUMEN
OBJECTIVE: The objective of this study was to evaluate the cognitive and physical impact of virtual reality (VR) integrated training versus traditional training methods in the domain of weld training. BACKGROUND: Weld training is very important in various industries and represents a complex skill set appropriate for advanced training intervention. As such, there has been a long search for the most successful and most cost-effective method for training new welders. METHOD: Participants in this study were randomly assigned to one of two separate training courses taught by sanctioned American Welding Society certified welding instructors; the duration of each course was 2 weeks. After completing the training for a specific weld type, participants were given the opportunity to test for the corresponding certification. Participants were evaluated in terms of their cognitive and physical parameters, total training time exposure, and welding certification awards earned. Each of the four weld types taught in this study represented distinct levels of difficulty and required the development of specialized knowledge and skills. RESULTS: This study demonstrated that participants in the VR integrated training group (VR50) performed as well as, and in some cases, significantly outperformed, the traditional welding (TW) training group.The VR50 group was found to have a 41.6% increase in overall certifications earned compared with the TW group. CONCLUSION: VR technology is a valuable tool for the production of skilled welders in a shorter time and often with more highly developed skills than their traditionally trained counterparts. APPLICATION: These findings strongly support the use ofVR integrated training in the welding industry.