Method for depositing particulate material onto a surface

A method for depositing a particulate material onto a surface, such that upon or following deposition the particulate material at least in part fuses to said surface and/or to itself to form a solid mass or coating on the surface, the method comprising the steps of:

• (1) placing said particulate material into a tubular member having a spraying end, and containing a gas or gas mixture;
• (2) causing at least one shockwave to travel along said tubular member towards said spraying end, and out of said tubular member towards said surface, at least some of said particulate material travelling with or adjacent said shock wave and being projected onto said surface at a velocity sufficient to cause upon impact with said surface at least partial deformation of said particulate material and/or said surface, and fusion with said surface and/or particulate material that has already been deposited on said surface, if present, wherein the shockwave is generated by a shockwave generator comprising a chamber and a valve, the chamber containing a gas or gas mixture having a pressure that is higher than a pressure of said gas or gas mixture in said tubular member, the gas or gas mixture in the chamber being released into said tubular member by opening the valve between the shockwave generator and the tubular member, thereby to generate said shockwave in said tubular member;
• and
• (3) optionally repeating steps (1) and (2) to deposit said material in a series of pulses.