An acoustic system for applying vibratory energy including a horn connected to an ultrasonic energy source. The horn defines an overall length and wavelength, and at least a leading section thereof is comprised of a ceramic material. The leading section has a length of at least ⅛ the horn wavelength. In one preferred embodiment, an entirety of the horn is a ceramic material, and is mounted to a separate component, such as a waveguide, via an interference fit. Regardless, by utilizing a ceramic material for at least a significant portion of the horn, the ultrasonic system of the present invention facilitates long-term operation in extreme environments such as high temperature and/or corrosive fluid mediums. The present invention is useful for fabrication of metal matrix composite wires.