WEB Change of the binding mechanism for clinched joints in the production cycleTuesday (22.09.2020) 10:55 - 11:10 Z: Special Symposia II Part of:
Today's multi-material design and the adaptability of a modern process chain require joining connections with specifically adjustable mechanical, thermal, chemical or electrical properties, whereby previous considerations have focused primarily on the mechanical properties. With clinching, the multitude of possible combinations of requirements, materials and component or joint geometry makes it impossible to determine these joint properties empirically. The technological parameters already stored in databases, such as the shear strength in relation to the materials used and the design of the joint, often serve only as a guide value that must be checked experimentally on the basis of the actual joint. The situation is similar with the thermal and electrical parameters and the properties actually achieved. As a result of this established and empirically based procedure, no model exists to date that considers all questions of joinability, i.e. the materials (suitability for joining), the design (joining safety) and the production (joining possibility) and allows a calculation of the achievable properties.
Therefore, it is necessary to describe the physical properties of the joint as a function of the three bonding mechanisms force closure, form closure and material closure in an application-specific manner using a suitable modelling approach.
This approach enables the illustration of the relationships along the causal chain "joint requirement - bonding mechanism - energy - joining parameters". In this way, the adaptability and adaptability of the mechanical joining technology can be improved.
A geometric comparison is made using metallographic cross sections, clinched joints (single-stage, round point without cutting component) of the aluminium material AA6014. The torsional testing of the rotationally symmetric clinching points for detection of the mechanical stress state (binding mechanism: frictional component) are qualified as examination methods and technological tests. By measuring the electrical resistance in the base material, in the clinch joint and during the production cycle (after clinching, before precipitation hardening and after precipitation hardening), this change in the stress state can also be detected.