Abstract: A method of forming and apparatus for a heat exchanger having a body of aluminum alloy having two sides with a groove machined in the body in the shape of a heat exchange tubing but of a dimension larger than the tubing. The tubing is placed in the groove and the space between the tubing and the groove is filled with boron nitride whereby corrosion problems are minimized and heat transfer enhanced. The method includes the steps of forming the cavity in at least one side of the body for inserting a tubing of a dimension less than the cavity, precoating the tubing in the cavity by spraying with boron nitride powder in a carrier, placing the heat exchange tubing in the cavity and filling the space between the wall of the cavity and the tubing with boron nitride powder, and bonding the two sides together.

Abstract: A waveguide joint with flanges bonded to a waveguide section. Each flange is divided into two pieces with internal knurling and corner projections to bite into the external waveguide corners. The flange pieces are pressed on while the bonding adhesive is cured.

Abstract: A waveguide joint with flanges bonded to a waveguide section. Each flange is divided into two pieces with internal knurling and corner projections to bite into the external waveguide corners. The flange pieces are pressed on while the bonding adhesive is cured.