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- Li, J., et al.
(författare)
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Exploring the mechanical strength of additively manufactured metal structures with embedded electrical materials
- 2015
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Ingår i: Journal of Materials Science and Engineering. - New York, NY : David Publishing Company. - 2161-6213 .- 0921-5093. ; 639, s. 474-481
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Tidskriftsartikel (refereegranskat)abstract
- Ultrasonic Additive Manufacturing (UAM) enables the integration of a wide variety of components into solid metal matrices due to the process induced high degree of metal matrix plastic flow at low bulk temperatures. Exploitation of this phenomenon allows the fabrication of previously unobtainable novel engineered metal matrix components.The feasibility of directly embedding electrical materials within UAM metal matrices was investigated in this work. Three different dielectric materials were embedded into UAM fabricated aluminium metal-matrices with, research derived, optimal processing parameters. The effect of the dielectric material hardness on the final metal matrix mechanical strength after UAM processing was investigated systematically via mechanical peel testing and microscopy. It was found that when the Knoop hardness of the dielectric film was increased from 12.1 HK/0.01 kg to 27.3 HK/0.01 kg, the mechanical peel testing and linear weld density of the bond interface were enhanced by 15% and 16%, respectively, at UAM parameters of 1600 N weld force, 25 µm sonotrode amplitude, and 20 mm/s welding speed. This work uniquely identified that the mechanical strength of dielectric containing UAM metal matrices improved with increasing dielectric material hardness. It was therefore concluded that any UAM metal matrix mechanical strength degradation due to dielectric embedding could be restricted by employing a dielectric material with a suitable hardness (larger than 20 HK/0.01 kg). This result is of great interest and a vital step for realising electronic containing multifunctional smart metal composites for future industrial applications. © 2015 The Authors.
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| 2. |
- Bournias-Varotsis, Alkaios, et al.
(författare)
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The effect of ultrasonic excitation on the electrical properties and microstructure of printed electronic conductive inks
- 2015
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Ingår i: 2015 38th International Spring Seminar on Electronics Technology (ISSE). - 9781479988600 - 9781479988594 ; , s. 140-145
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Konferensbidrag (refereegranskat)abstract
- Ultrasonic Additive Manufacturing (UAM) is an advanced manufacturing technique, which enables the embedding of electronic components and interconnections within solid aluminium structures, due to the low temperature encountered during material bonding. In this study, the effects of ultrasonic excitation, caused by the UAM process, on the electrical properties and the microstructure of thermally cured screen printed silver conductive inks were investigated. The electrical resistance and the dimensions of the samples were measured and compared before and after the ultrasonic excitation. The microstructure of excited and unexcited samples was examined using combined Focused Ion Beam and Scanning Electron Microscopy (FIB/SEM) and optical microscopy. The results showed an increase in the resistivity of the silver tracks after the ultrasonic excitation, which was correlated with a change in the microstructure: the size of the silver particles increased after the excitation, suggesting that inter-particle bonding has occurred. The study also highlighted issues with short circuiting between the conductive tracks and the aluminium substrate, which were attributed to the properties of the insulating layer and the inherent roughness of the UAM substrate. However, the reduction in conductivity and observed short circuiting were sufficiently small and rare, which leads to the conclusion that printed conductive tracks can function as interconnects in conjunction with UAM, for the fabrication of novel smart metal components.
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