Electrical properties of Al-Si surface composites through surface mechanical alloying on severe plastic deformed Al substrates

Abstract

Surface mechanical alloying ‘SMA’ with Si powder on Al was used to achieve surface composite with improved dielectric properties compared with coarse-grained and annealed Al composites. Measured Dielectric constant ε', dielectric loss ε" and Capacitance CμF versus increasing frequencies (105-108 Hz) exhibit a frequency dependent behavior of composite containing Al-Si solid solution in a voltage range from 0.1 to 0.5 V at room temperature. Found that an increase of Si content in surface composite results in ε, tan δ & C increase due to formed solid solutions between Al & Si after SMA on pre-severe plastic deformed Al substrates. Concluding the important role played by the severe plastic deformed microstructure of Al electrode in controlling dielectric properties of Al surface containing Al-Si composite.