VW Applied Sciences, Volume: 2, Issue: 2, 87-91
Received: April 18, 2020
Accepted: May 02, 2020
Published online: May 13, 2020
Jawad Abid1, Hassan Raza2*, Awais Akhtar2, Ghulam Abbas Gohar1, Sana Ullah2, Muhammad Akram1, Yasir Raza1, Muhammad Dawood Bukhari1
1Department of Mechanical Engineering, COMSATS University Islamabad, Sahiwal Campus, Pakistan
2Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong
*Corresponding Authors Email: hassan.raza@connect.polyu.hk, Tel: +85255190485
Abstract: In this study, the effect of surface roughness on adhesive bonding of aluminum (AL 6061 T6) substrates is investigated to determine the required bond strength between the adhesive and adherends interface. Quality of AL 6061 T6 lap shear joints (adherend surface preparation) is achieved by mechanical abrasion using diverse grades of silicon carbide sheets (P 320C, P 220C, and P 180C). Lab grade acetone is utilized for the removal of impurities from the substrate surface while Loctite 4090 is served as adhesive to bond lap shear joints. The surface roughness of the substrates is measured by using a profilometer (SURFTEST SJ-210). Experimental testing of adhesively bonded specimens with diverse surface roughness is conducted on Universal Testing Machine (UTM) to measure the shear strength. The results show that aluminum adherends pretreated with P220 C achieve maximum adhesion bond strength up to 34.45 MPa at surface roughness of Ra=1.55 μm, but further increase in surface roughness from Ra=1.55 μm to Ra=2.4 μm causes 13.7% decrease in shear bond strength. Furthermore, the specimens without pretreatment achieve minimum shear bond strength up to15.23 MPa at surface roughness of Ra=0.03 μm. It was concluded that with the increase in surface roughness of the adherends up to a certain limit, bond strength also increases, and locus of failure shifted from adhesive – adherend interface to within the adhesive.
