SINA - Sensorintegration in Aluminum Cast

Abstract:

In the Project „SINA“ - Sensorintegration in aluminum cast - piezoresistive sensors for the direct integration in aluminum cast will be developed. Integration taking place during the casting process produces a shape connection between the Sensor and the component which allows the measurement of strain directly at the relevant place in the component.

Objective:

The basic aim of this project at IMSAS is to do research on new combinations of technology and material which allow for the fabrication of sensors with a high thermomechanical load capacity to endure a temperature of up to 700 °C during integration into an aluminum cast. Mechanical and thermal influence on the component by the foreign body effect of the integrated sensor shall be investigated and minimized. To fully integrate these sensors into the component, new mounting and connection technology has to be developed in order to lead the electrical wires from the sensor via component to the outside/ through the component to the outside.

Project Description:

It is common to mount strain gauges for structural health monitoring on the surface of components, where they are exposed to environmental influences and therefore have to be protected. In the future sensors will be integrated in intelligent components. Thus, sensors are naturally protected against various influences like rockfall, dust and saltwater.

Sensors on Silicone Substrate have a high failure rate due to different elongation coefficients of aluminum (α_Al=21E-6 1/K) which is by the factor 8 higher than the elongation coefficient of silicone (α_Si=2,6E-6 1/K), hence stress during the cooling phase can lead to cracks in the brittle silicone substrate. Furthermore, widely varying E-Modules can cause stress in the aluminum matrix under load, which weakens the component. This foreign body effect has to be investigated further and minimized by new combinations of technology and material.

To integrate the sensors completely into the component, a good mounting and connection technology has to be developed, which which has to withstand the integration process and is temperature stable. The foreign body effect has to be considered here as well. This project is done in cooperation with the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM). The IFAM is focusing on the requirements for the casting process, on the positioning of sensors in the mold and on the simulation of the casting process.