High Volume Production of PZT Fiber Arrays for Direct Functional Integration into Metal Structures

Abstract

A new concept for electromechanical coupling of piezoceramic to metal structures is enabled with the technology of joining by forming. This approach allows for the manufacturing of so-called piezo-metal modules. To make the manufacturing process ready for series production, it is necessary to fabricate lead zirconate titanate (PZT) fiber arrays with high geometric accuracy. In addition, the aim is to design the PZT fiber arrays so that they are usable with either piezoelectric transversal, longitudinal, or shear mode to enable different application options. In particular, the realization of the shear mode offers new application potentials in comparison to commercially available products. This paper presents both, a high volume production method, and the specific order for the production steps of PZT fiber arrays to achieve the different piezoelectric modes. In particular, the usable piezoelectric effects are determined by the order of the coatings of electrode and insulating layers as well as the direction of the polarization. Experimentally produced samples are tested in functional tests before and after the joining by forming process. The results verify the proof of the production method of PZT fiber arrays with a high accuracy. Furthermore, structurally integrated PZT fiber arrays demonstrate the functional use of the three piezoelectric modes in the plane of an aluminum sheet. Fabricated piezo-metal modules with transversal mode and shear mode are successfully verified in sensory function. The longitudinal mode is tested in actuator function. During the tests, failures for the insulation layer are identified. These can be eliminated with a modified manufacturing process, which is proposed.