DocumentCode :
2504281
Title :
A study on the effect of surface roughness on the strength of single lap joints
Author :
Gomatam, Rajesh ; Sancaktar, Erol
Author_Institution :
Dept. of Polymer Eng., Akron Univ., OH, USA
fYear :
1998
fDate :
28-30 Sep 1998
Firstpage :
362
Abstract :
Summary form only given. Many surface treatments to improve adhesion roughen the surface. Treatments such as abrasion and etching remove the weak boundary layer and improve wetting behavior. Liquid adhesives that are spread during application do not ensure removal of air from cavities on the surface. Adhesive penetration into substrate pores is influenced by capillary forces and retarded by viscosity. Surface roughness can affect adhesive spreading and contact angle. In order to investigate aspects of surface roughness, surface profile, resin viscosity, and surface morphology, experiments were conducted using two steels (1018 cold rolled and hot rolled weld steel). Four surface modifications were performed on these samples by grit blasting at 552 kPa and 276 kPa from a distance of 25.4 mm and chemical etching using chromic acid for 2 mins and 10 mins. Crossed patterns were also obtained by an etch technique which involved changing the metal sample dip angle into the etch solution. Two resins were used to assess viscosity effects in interaction with different surface topographies. Contact angles were measured on all surfaces using these resins. Metal specimens were bonded under pressure and oven cured at 121°C for 2 hours. To gain insight into the effect of surface topography, SEM was used to observe the modified surfaces. Average roughness was measured using a profilometer and surface profiles were obtained for all samples. The strength and displacement values were measured at crosshead speeds of 1 and 100 mm/min, to assess the interrelation between failure mechanisms and joint displacements, surface topography and resin viscosity
Keywords :
abrasion; adhesion; adhesives; assembling; capillarity; contact angle; etching; failure analysis; heat treatment; mechanical strength; polymer films; rough surfaces; surface topography; viscosity; wetting; 10 min; 121 C; 2 hr; 2 min; 25.4 mm; SEM; abrasion; adhesion; adhesive contact angle; adhesive penetration; adhesive spreading; average roughness; capillary forces; chemical etching; chromic acid etch; cold rolled steel; crossed patterns; crosshead speeds; etch solution; etching; failure mechanisms; grit blasting; hot rolled weld steel; joint displacements; liquid adhesives; metal bonding; metal sample dip angle; modified surfaces; oven cure; profilometer; resin viscosity; single lap joint strength; single lap joints; steels; substrate pores; surface cavities; surface modifications; surface morphology; surface profile; surface roughening; surface roughness; surface topography; surface treatments; viscosity; viscosity effects; weak boundary layer; wetting behavior; Adhesives; Etching; Resins; Rough surfaces; Steel; Surface morphology; Surface roughness; Surface topography; Surface treatment; Viscosity;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Adhesive Joining and Coating Technology in Electronics Manufacturing, 1998. Proceedings of 3rd international Conference on
Conference_Location :
Binghamton, NY
Print_ISBN :
0-7803-4934-2
Type :
conf
DOI :
10.1109/ADHES.1998.742054
Filename :
742054
Link To Document :
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