Application of the process of joining sheet by mechanical cold forming (clinching) using dissimilar materials

Abstract

In the metalworking industry in general, the need to join components made of sheet metal is very common. The automotive sector, for example, needs to join components made of sheet metal to assemble vehicle bodies. The aeronautical sector needs to join sheets, mainly aluminum, when assembling aircraft. In white goods, there is a need to join low-carbon steel sheets that make up a wide range of household appliances, as well as other sectors such as metal structures, packaging and others. The joining of sheet metal components can be done through some permanent joining process, such as welding and riveting; or by some type of detachable connection, made by screw, nut, stud, pin, among others. A joining technique that has been gaining ground in the industry is plastic deformation joining. Groche et al. (2014) reviewed this technique and present the various existing variations. The most common is known as clinching union. According to Varis (2006), it emerged in the 1980s in an automotive industry in the assembly of chassis. The technique consists of cold joining sheets through the action of a punch that plastically deforms the sheets against a die. The deformation produces an interlook region that joins the sheets, giving the appearance of a spot weld. Sarmento and Pereira (2012) cite the main advantages of this technique: (I) it allows joining a vast amount of materials including metals with non-metals; (II) lower distortions, embrittlement and residual stress; (III) high process repeatability and simple quality control, and (IV) safe working environment.