Experimental evaluation of T-peel strength on functionally graded Al5083 and HDPE tri-laminated composites fabricated by colding-assisted friction stir additive manufacturing

Functionally graded composites offer impressive promise in overcoming the inherent weaknesses of Metal-polymer hybrid structures. In this study, functionally graded 5083 aluminum (Al5083) and high-density polyethylene (HDPE) tri-laminated composites were fabricated by colding-assisted friction stir additive manufacturing (CA-FSAM) and friction stir additive manufacturing (FSAM). Functionally graded laminate composites have been used to overcome these drawbacks by varying the thickness of the raw laminate. The thickness changes in the user sheets were functionally 0.75 mm compared to the previous laminate. Finally, the initial sheets were transformed to three thicknesses: 3, 2.25, and 1.5 mm. The bond strength between the sheets was measured using the T-peel test. In the T-peel test, the initial crack length was 25 mm and the length of the weld zone was 111 mm. The results showed that the bond strength between the laminates improved with cooling after the CA-FSAM process. The bond strength is essentially determined by the amount of covalent bonding, which, in turn, is a function of the density on the treated surface. Dislocation forest at the surface of the tri-laminate composite can be considered a consequence of T-peel test. The joining mechanism could be ascribed to mechanical interlocking, adhesion bonding at the interface of the Al5083 alloy and HDPE polymer, and metal-chip reinforcement in HDPE of the stir zone. The maximum force (F_max) obtained in the FSAM and CA-FSAM specimens were 1057.58 and 1254.20 N, respectively. Average force of T-peel test (F_{avg peel}) obtained in the FSAM and CA-FSAM specimens was 984.36 and 1024.32 N, respectively.