Optimization of Wood Welding Parameters for Australian Hardwood Species

Optimal linear wood welding parameters along the end-grain-to-end-grain faces were determined for Eucalyptus saligna, Eucalyptus pilularis, and Corymbia maculata. Joints made using Eucalyptus saligna showed a significant interaction between welding time (WT), amplitude (WA), and pressure (WP). A preheating phase of 3 s at 0.4 MPa WP and 0.75 mm WA coupled with a WT of 2 s at 2.0 MPa WP and 1.5 mm WA provided the best shear strength results of 5.1 MPa. Joints made using Eucalyptus pilularis and Corymbia maculata snapped once the holding pressure was removed, suggesting that end-grain-to-end-grain welded fibers cannot withstand the thermal stresses generated when the surface to be welded is too small (e.g., 13.5 cm2). However, grain orientation had a significant effect on the weld mechanical properties, as very strong edge-grain-to-edge-grain joints were produced with Eucalyptus pilularis and Corymbia maculata (9.5 and 6.2 MPa, respectively). The joints made of Eucalyptus saligna also showed significant improvement (7.3 MPa). Energy efficient combinations were usually those involving low WA and short WT, as WP had a marginal effect on energy consumption during the welding process