Thermoplastic vibration welding: Review of process phenomenology and processing–structure–property interrelationships

Abstract

Vibration welding offers a robust method for physically joining thermoplastics to fabricate complex hollow assemblies from simpler injection‐molded articles without using an external heat source, adhesives, or mechanical fasteners. Vibration welding involves a complex interplay of several phenomena—solid (Coulomb) friction, melting, high strain‐rate, pressure‐driven, strong (high‐strain) melt flows, solidification, and microstructure development—which ultimately govern the strength and integrity of the weld. Defects in the weld region may lead to catastrophic failure of the welded assembly. In this article, the current understanding of the processing–structure–property relationships in the context of vibration welding of thermoplastics and polymer‐matrix composites is reviewed. Experimental as well as analytical methods of investigation of the vibration welding process phenomenology are presented. The interrelationships between the microstructure in the weld region and the resulting weld strength and fatigue behavior are then discussed in the light of this phenomenological information for neat polymers, filled polymers, polymer blends, and foams. This review is also aimed at identifying the areas requiring further investigation with regard to understanding vibration welding phenomenology and weld structure–property relationships. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

Influence of process parameters on mechanical performance and bonding area of AA2024/carbon-fiber-reinforced poly(phenylene sulfide) friction spot single lap joints

“…In addition to the rotational speed of the tool, which causes the reduction in the viscosity of the PPS molten layer, the axial force in the spot area (as a result of the JP) facilitates the outward flow of the PPS layer. Similar behavior was reported for spin welding [28] and vibration welding [31] of thermoplastics for which higher welding pressure causes faster lateral flow of the molten polymer. It seems that in FSpJ, both factors, i.e., high rotation of the tool and large JP, are required to increase the spreading of the molten polymer.…”

Vibration Welding of Amorphous Thermoplastic Nanocomposites

“…The process of joining may be mechanical fastening, and physical and chemical bonding [1]. The method adopted for joining the materials depends on the main parameters like the type of materials to be joined, size, dimensions of the joining area, production rate, service conditions, performance requirements, cost constraints, etc.…”

“…[2]. Thermoplastics have the characteristics to lend themselves to complex shaping, which involves large strain deformations, small radii of curvature, and sharp thickness gradients through the processing operations such as injection molding, extrusion, and thermoforming [1]. These characteristics of the polymer make them to be used widely for automobile application, in order to minimize the weight and cost of the product.…”

Microscopic analysis of the morphology of seams in friction stir welded polypropylene

“…Similar to metals the welded seam and welding zone formed in polymers depends strongly on the developing morphology, i.e. on the supermolecular structure generated [6]. In the case of all welding processes the temperature necessary for welding is at or above the melting range of the base material.…”

“…This triggers melting and crystallization and vari-ous deformation processes in the molten and heat affected layers, respectively, similar to other polymer processing technologies [7,8]. Various friction welding methods were adapted for polymeric materials [6], and we have also dealt with the application possibilities of FSW in polymers [9]. Hot gas welding is an important and commonly used joining method.…”