Effect of hygrothermal environment on properties of induction welding joint of carbon fiber reinforced polyphenylene sulfide laminate

The carbon fiber reinforced polyphenylene sulfide (CF/PPS) composite laminate was taken as the research object, and the induction welding method was used to weld the CF/PPS laminate. It was focused on the effect of hygrothermal on the welded joint performance of the CF/PPS laminate. The experimental results show that the PPS resin does not undergo chemical changes before and after moisture absorption. At room temperature, the shear strengths of the welded joints gradually decrease with the increase of moisture absorption time, and compared with the dry welded joints, they are reduced by 15%, 18%, 23%, 32%, and 38%, respectively. The wet stress increases at the interface of the stainless steel mesh, resin matrix and carbon fiber, which weakens the bonding performance of the welded joint interface, and affects the failure mode of the welded joint. Under the environment of 120℃, the shear strength values of the welded joints with different moisture absorption times decrease by 12%, 15%, 22%, 37% and 44%, respectively. High temperature and high humidity make the thermal stress and wet stress at the interface of the stainless steel mesh, resin matrix and carbon fiber greater, which aggravates the damage of interface bonding performance. Interface debonding is the main failure form of the welded joints.