Surface Structurization of Metallic Inserts for Enhancement of Polymer-Metal Joints

Abstract

In this work, aluminum inserts were structurized and joined with polyamide 6 with 15% by weight of short glass fibres (PA6 GF15) by using the injection-molding technique. The metal parts, made of aluminum grade 6061 were surface structurized by means of plastic forming with shaped inserts and also by laser microablation. Plastic forming was made at the preset pressing pressure values: 5 MPa, 10MPa, 15 MPa and 18 MPa (in two-side mode) meanwhile laser beam speed was set as: 75, 150, 250 and 350 mm/s with grooves interline distance of 0,2; 0,4 and 0,8 mm (for one side and both sides regime). The joints made of aluminum/PA6 GF15 were mechanically tested in a tensile-lap-shear test. For estimation of the basic shape and parameters of grooves contact surface roughness tester was used. Microscopic observation with optical microscope confirmed that during injection stage polymer materials filled the grooves shape in both plastic formed as well as laser treated aluminum inserts. The maximal values of the joint’s failure force under tensile-shear tests were achieved for two-side laser micropatterned samples (for scanning speed 150 mm/s and interline distance 0,4 mm) and it was 1494 N. The ultimate force detected for samples with plastic formed inserts was almost four times smaller and it was 325 N.KeywordsPolyamide 6AluminumHybrid jointOvermoldingLaser engravingSurface structurization