There is an ongoing need for economical, lightweight, stable mirror substrates which are capable of high optical performance in the visible and the infrared. Metal matrix composite (MMC) materials were selected as one class of materials suitable for meeting such needs. The economical fabrication of MMC materials into lightweight mirror structures requires unique machining and heat treating methods. These methods were developed for the fabrication of a high quality MMC lightweighted mirror which is described below.
"Fabrication Of A Metal-Matrix Composite Mirror", Proc. SPIE 0966, Advances in Fabrication and Metrology for Optics and Large Optics, (29 January 1989); doi: 10.1117/12.948056; https://doi.org/10.1117/12.948056