Abstract
The footprint of a cold spray beam has narrow dimensions and a large particle density, which lead to fast growth of deposit on precise locations. Cold spray produces compressively stressed coatings which lead to well bonded ultrathick coatings over many substrates. Since cold spray produces dense coatings with wrought-like microstructure, it can be used to produce large bulk forms. Two different bulk forms were produced: (i) ultrathick coatings strongly bonded to substrates and (ii) free standing structures (FSS). Both forms were post machined to obtain net-shape or near-net-shape articles. Bulk forms up to 60 mm were produced with many powders including metals, alloys and composites. Well bonded ultrathick coatings were produced over many substrates including aluminum, copper, SS, etc. FSS, including pipes, plates, etc, were produced by fabrication of a mandrel, spray coating bulk forms and removal of the mandrel. Coatings in the as-sprayed condition were machined and fine features such as grooves incorporated to obtain net-shape articles.
