An investigation on microstructural features and bonding strength of magnesium-based multifunctional laminated composite developed by friction stir additive manufacturing

Abstract

Recently, the demand for lightweight multilayered parts in electronics and biomedical fields has been accelerated and shown great interest in understanding the combined effect of multilayered materials. However, these industries are still facing the challenge of developing dissimilar multilayered materials that can be suitable for biomedical applications. In this context, magnesium emerges as a promising biocompatible material used for several biomedical applications. However, the issues related to joining magnesium alloys with other similar materials still need to be solved. Moreover, friction stir additive manufacturing (FSAM) occupies a niche domain for developing or joining biocompatible materials such as magnesium alloys with low weight and high strength. Therefore, the present work highlights the development of a multipurpose three-layered multifunctional laminated composite plate of magnesium-based AZ31B–Zn–Al 1100 through the FSAM route. Microstructural and morphological examinations were carried out by light microscopy and FESEM equipped with EDS analysis and line mapping. Moreover, the grain refinement at the interfaces during the FSAM was also addressed using the electron backscattered diffraction (EBSD) study. Further, investigation on mechanical properties such as tensile test with fractography analysis and microhardness variation at the cross-section of the built-up section has been investigated. Furthermore, the corrosion and tribological analysis was also performed, and a 3D profilometer was used to visualize the corroded and worn-out surfaces. The microstructural results revealed that the average grain size of 6.29 μm at interface AZ31B–Zn and 1.21 μm at interface Zn–Al 1100 occurred, improving the bonding strength and overall properties. The tensile strength has occurred as 171.5 MPa at 15.5% elongation, whereas maximum microhardness is reported as 105 HV at the interface of AZ31B–Zn and 84.6 HV at the interface of Zn–Al 1100. The corrosion rate was calculated as 0.00244 mm/day, and the average coefficients of friction (COF) for both the interfaces, such as AZ31B–Zn and Zn–Al 1100, are 0.309 and 0.212, respectively.

A Framework to Simulate Friction Stir Additive Manufacturing (FSAM) Using the Finite Element Method

“…It is notable that during the sticking condition some parts of the materials adhere to the tool. Providing the layers are added to each other, a larger heat zone at the workpiece is observed because of the preheating at the initial steps [ 42 , 43 , 44 , 45 ]. As with the previous layer, a sliding condition is also present far from the center of the workpiece.…”

“…In contrast, using the Eulerian model decreases the computational costs, and shows a similar pattern for the simulation. As can be seen, in order to optimize the model, the mesh sizes at the center of the workpiece are larger than at the sides [ 42 , 43 , 44 , 45 ].…”

“…Since the material at the center of the workpiece faces a disparity, its cooling rate is faster than the other parts. The most important reason for this disparity is the higher material velocity at the center of the workpiece that results in lower heat generation and a higher cooling rate [ 43 , 44 , 45 , 46 , 47 ]. In the cooling phase, this thermal behavior appears across the workpiece, and this causes larger rings (see Figure 6 ).…”

“…Micromachines 2024, 15, x FOR PEER REVIEW 11 of 17 pattern for the simulation. As can be seen, in order to optimize the model, the mesh sizes at the center of the workpiece are larger than at the sides [42][43][44][45].…”