Abstract
In this paper we have used laser powder bed fusion (PBF) to manufacture and characterize metal microwave components. Here we focus on a 2.5 GHz microwave cavity resonator, manufactured by PBF from the alloy AlSi10Mg. Of particular interest is its thermal expansion coefficient, especially since many microwave applications for PBF produced components will be in satellite systems where extreme ranges of temperature are experienced. We exploit the inherent resonant frequency dependence on cavity geometry, using a number of TM cavity modes, to determine the thermal expansion coefficient over the temperature range 6–450 K. Our results compare well with literature values and show that the material under test exhibits lower thermal expansion when compared with a bulk aluminium alloy alternative (6063).
Highlights
Additive manufacturing (AM) is a modern fabrication process that enables three-dimensional components to be built using multiple twodimensional layers
Components produced by laser powder bed fusion (PBF, one form of AM) are being utilised in satellite feed chains due to the ability to achieve up to 99.8% density but with a 50% weight reduction compared to the subtractive manufactured equivalents [1], AM adoption in this field is still in its infancy [2]
This study uses a fractional frequency shift method to evaluate the true coefficient of thermal expansion (CTE) of an aluminium cylindrical microwave cavity produced through PBF over a wide temperature range (6–450 K) without the need for strict calibration. This is the first time that CTE has been assessed over a wide range of temperature, as is appropriate for spacebased components, using a passive microwave structure that can be adopted in a satellite communications system
Summary
Additive manufacturing (AM) is a modern fabrication process that enables three-dimensional components to be built using multiple twodimensional layers. For aluminium (of bulk conductivity 2.63 × 107 S/m) the skin depth at 2.5 GHz is calculated to be ≈2 μm, and so even micro surface features can have a significant impact on current flow and microwave loss. To overcome these losses, post processing techniques such as machine polishing [10] and silver plating are often employed [9,11,12]. This is the first time that CTE has been assessed over a wide range of temperature, as is appropriate for spacebased components, using a passive microwave structure (produced by PBF) that can be adopted in a satellite communications system
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
