Speaker
Description
Indirect additive manufacturing opens up new methodologies for producing innovative systems to unusual requests, like self-healing. In the envisaged application as aeronautic, the matrix must contain sensors and/or actuators to detect cracks (sensors) and eliminate them (actuators). In this study, the material extrusion (MEX) technology was selected for shaping. This technology is complemented by debinding and sintering stages. The integration of superelastic NiTi shape memory alloy wires (SMA), as crack sensor, became possible by developing step-by-step a part/system with integrated sensors. The metallic matrix was shaped by a filament composed of 60% (vol.%) aluminum alloy powders (AA 7050), binder and additives; and the NiTi wires were introduced. The aim of the study is to optimize the printing strategies to integrate the sensor in the aluminum alloy matrix, ensuring its performance during the application. Whatever the strategies for NiTi crack sensor incorporation, they must guarantee the best adhesion between matrix and sensor. The AA 7050 and NiTi wire sensors, during debinding and sintering temperatures do not promote the formation of other phases. Therefore, the shape memory alloy properties are preserved. X-ray microtomography is the elective test technique used to evaluate the adhesion efficiency between matrix and crack sensor, before and after sintering. Moreover, the sensor performance is analyzed by electrical resistivity measurements.
CrackFree - Towards self-repairing metallic materials
| Speaker Country | Portugal |
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