Manufacturing Process Design of a Microchannel Solar Receiver using Electrically-Assisted Embossing

Abstract Manufacturing process design (MPD) represents a design-oriented approach to manufacturing engineering. In this paper, Haynes 230 (H230), a solid solution strengthened Ni-based superalloy, was chosen to meet the material requirements of a microchannel solar receiver (MSR) needed to increase the efficiency and reduce the cost of solar thermal power generation. A MPD was developed to enable the cost-effective production of the MSR. This MPD revealed the need to increase the height-to-diameter aspect ratio of posts using electrically-assisted (EA) forming to reduce the mass and cost of MSR fluidic interconnects. Preliminary efforts to validate the MPD through fabrication of sub-scale MSR test articles resulted in several process failures. Among them, die and platen failure, accelerated creep during bonding due to grain refinement as a result of forming. This resulted in poorly formed channels in the final bonded devices. Suggestions for EA forming die material and adjusted forming setup geometry to reduce feature variability are discussed. Results suggest the need to perform solutionizing heat treatments of H230 after EA forming, prior to diffusion bonding, in order to meet the requirements of the MSR. Suggestions for EA forming die material and adjusted forming setup geometry to reduce feature variability are discussed