An improved thermal spray apparatus and method of promotes mixing of axially fed particles in a carrier stream with a heated effluent stream without introducing significant turbulence into either the effluent or carrier streams. An axial injection port includes a plurality of chevrons at the distal end of the port. The chevrons are located radially around the circumference of the distal end of the axial injection port to increase the shared area between the two flow streams at the outlet of the port.