Session Sheet - 13th International Conference on the Technology of Plasticity (ICTP 2021): Joining by Forming and Deformation II

13th International Conference on the Technology of Plasticity (ICTP 2021): Joining by Forming and Deformation II
Program Organizers: Glenn Daehn, Ohio State University; Libby Culley, The Ohio State University; Anupam Vivek, Ohio State University; Jian Cao, Northwestern University; Brad Kinsey, University of New Hampshire; Erman Tekkaya, TU Dortmund; Yoshinori Yoshida, Gifu University

Tuesday 10:20 AM
July 27, 2021
Room: Virtual: Room B
Location: Virtual

Session Chair: Zhichao Huang, East China Jiaotong University

Mechanical Properties of Aluminum-stainless Steel Bimetal Composite Fabricated by Extrusion Process: Kai Soon Fong¹; Atsushi Danno¹; Dharmesh Kumar¹; Suwat Jirathearanat¹; Wee Kit Ong¹; ¹Singapore Institute of Manufacturing Technology
    In this work, an indirect extrusion process was designed to manufacture a stainless steel reinforced aluminium composite. The design utilized a feeding mandrel to prevent the deformation of the stainless steel wire and to facilitate the embedding of the wire within the aluminium alloy during extrusion. By using this method, a 12 mm diameter 6061 aluminium alloy embedded with a 2 mm diameter 304 stainless steel wire was successfully fabricated. Energy-dispersive X-ray spectroscopy revealed that aluminium and iron elements had diffused into the interfacial layer between the aluminium-stainless steel to induce some degree of metallurgical bonding. The yield strength, tensile strength and elongation to failure of the extruded composite after solution and aging heat treatment were 343.8±5.5MPa, 405.3±5.1MPa and 18.0±1.3%, respectively. As compared to extruded aluminium, yield strength, ultimate tensile strength and elongation to failure were improved by 41.8%, 31.6% and 6.3%, respectively. This result suggests that the composite material has better strength and toughness as compared to aluminium alone.

Spot Butt Friction Stir Welding of Thin Stainless Steel Sheets: Hidenori Yoshimura¹; Toshiki Muraoka¹; Takuya Miura²; Masato Okada²; Yoichi Takahashi³; Masaaki Otsu²; ¹Kagawa University; ²University of Fukui; ³National Institute of Technology, Kagawa College
    Spot butt friction stir welding of thin stainless steel sheets is proposed. The used material was 18%Cr-8%Ni stainless steel and thickness of the sheet was 0.1mm. In case of the thin metal sheet of such thickness, especially not overlap but butt joining, there are few previous researches. The difficulties are sheet rigidity, tool shape and tool position control. Because it is difficult to form the probe having complicated shape accurately, the semispherical shaped tool was used. The tool was rotated and moved to the position decided by the prescribed static pushing load. To avoid adhesion between sheets and a backing plate, a ceramic backing plate was selected. Effects of the tool rotation speed and the prescribed pushing load on weldability were examined. Only when the joining was successful, the characteristic load change by metallic adhesion between the tool and sheets was observed.

Temperature and Deformation Modeling for the Friction Stir Welding Process in AZ31 Magnesium Alloy: Rafael Giorjao¹; Julian Avila²; Eduardo Monlevade³; Antonio Ramirez¹; Andre Tschiptschin³; ¹The Ohio State University; ²UNESP; ³USP
    Friction stir welding (FSW) is a solid state joining process that uses frictional heat generated by a rotating tool to join materials. Yet, the tool role in the material processing, due to complex material flow and its difficult modeling, is still not entirely understood. In this matter, a computational solid mechanics numerical model aimed to simulate the FSW process in an AZ31 alloy is proposed. This model uses an Arbitrary Lagrangian-Eulerian code in two different pin profile tools, with threaded and unthread pins. Point tracking technique was applied in the model to provide deformation, velocity and temperature data both conditions. It was noticed that velocity and strain rate have higher values in the threaded condition. Finally, the point tracking data was applied in a grain size model and compare to the real microstructure, showing good consistency of the predicted temperature and deformation behavior calculated by the model.

Friction Stir Welding Applied in Joining of Armor Steel: Antonio Ramirez¹; William Evans²; Rafael Giorjao¹; Mike Eff³; Martin McDonnell⁴; ¹The Ohio State University; ²NASA; ³EWI; ⁴Combat Capability Development Center - Ground Vehicle Systems Center
    Friction Stir Welding (FSW) is a solid-state joining technique that utilizes non-consumable tool to stir two materials into a joint. In this study FSW parameters were developed and used to weld Wrought Homogeneous Armor steel. Metallography, micro hardness indention, and thermal modeling was also employed to predict the joint’s properties. Through this work parameters were down-selected to make defect free weld. Examining the micrographs and SEM images, the microstructure appeared to be fully martensitic. The martensite found in the stir zone (SZ) and heat affected zone has undergone auto-tempering as well. When examining the micro hardness profile of the weld, it appears that the SZ hardness is close to that of the base metal. This would indicate that some level of tempering is occurring during the welding process, leaving a tempered martensitic microstructure.

Elastoplastic Finite Element Analysis of Multi-body Processes for Joining Mechanical Parts: ManSoo Joun¹; Jaedong Yoo¹; SukHwan Chung²; Renganathan Sekar²; ¹Gyeongsang National University; ²MFRC
     Fabricating light weight assembly of auto-parts is of great importance and joining technology using plastic deformation is very attractive because of high strength and structural reliability. In developing such assembling processes, prediction technology with high accuracy is essential to optimize the structural system and minimize the manufacturing cost. However, the related technologies are not still sufficiently developed for the sake of application because of complexity of the problem. Joining and other assembly processes highlight the requirement of a multibody metal forming simulation.In this paper, an improved methodology of conducting elastoplastic finite element analysis of multi-body processes is given and several examples are solved in terms of interfacial stresses or residual stresses and solution accuracy. A multi body simulation of an assembly process of the first-generation hub bearing unit is carried out and validated to illustrate the applicability of this methodology.