Evaluation of process parameters for poly(ether ether ketone) to poly(ether ether ketone) friction welded joint

Poly(ether ether ketone) is a semicrystalline organic polymer. It has widely been used as high-performance engineering plastic owing to its high melting point (343 degrees C), excellent mechanical strength, and outstanding chemical resistance. Therefore, poly(ether ether ketone) and its composites have shown lots of applications in aerospace and medical fields. However, its application is restricted due to poor strength at the mechanically joint components. Thus, this scope leads us to study an alternative method of the joint process that will lead to finding a new joining process for poly(ether ether ketone)-based materials. In this study, a solid-state joining process was conducted to join two poly(ether ether ketone) rods by a friction welding process. Here, we statistically optimized the values of forge load, friction load, and friction welding time as 100 N, 450 N, and 8 s, respectively, which have more influence on tensile stress and hardness of the material after the friction welding process. It has been found that the forge load had the highest influence and the forge time had the least influence on tensile strength. Their optimal values were calculated after considering the trend in hardness values by statistical analysis using Minitab software. However, after the optimal values, the above parameter showed a negative effect on the high tensile stress due to the change in crystallinity of the friction welding processed poly(ether ether ketone) as confirmed by X-ray diffraction and thermal analyses.