Deposition of Coatings on Substrates

An apparatus for carrying out a coating process for the deposition of a layer of a first material onto a substrate of a second material, the second material optionally being different from the first material, the process including the steps:

• entraining powder particles of the first material into a carrier gas flow to form a powder beam directed to impinge on the substrate, thereby defining a powder beam footprint region at the substrate:
• causing relative movement of the powder beam and the substrate in a movement direction to move the powder beam footprint relative to the substrate to deposit the layer of the first material:
• and
• operating a laser source to direct a laser beam along a laser beam direction to provide a laser beam footprint to cause direct. local heating of at least one of the forward substrate region and the powder beam footprint region.
• the laser beam direction being defined with reference to a plane coincident with or tangential to a surface of the substrate at the centre of the laser beam footprint in terms of an elevation angle from the plane to the laser beam direction and in terms of an acute azimuthal angle from the movement direction to the laser beam direction,
• wherein the elevation angle is 80° or less and the azimuthal angle is ±60° or less,
• wherein in the apparatus there are provided at least three laser sources arrayed around the powder beam footprint, the angular spacing between the laser sources being 120° or less.

An apparatus for carrying out a coating process for the deposition of a layer of a first material onto a substrate of a second material, the second material optionally being different from the first material the process including the steps:

• entraining powder particles of the first material into a carrier gas flow to form a powder beam directed to impinge on the substrate, thereby defining a powder beam footprint region at the substrate;
• causing relative movement of the powder beam and the substrate in a movement direction to move the powder beam footprint relative to the substrate to deposit the layer of the first material:
• and
• operating a laser source to direct a laser beam along laser beam direction to provide a laser beam footprint to cause direct, local heating of at least one of the forward substrate region and the powder beam footprint region,
• the laser beam direction being defined with reference to a plane coincident with or tangential to a surface of the substrate at the centre of the laser beam footprint in terms of an elevation angle from the plane to the laser beam direction and in terms of an acute azimuthal angle from the movement direction to the laser beam direction,
• wherein the elevation angle is 80° or less and the azimuthal angle is ±60° or less,
• wherein in the apparatus there are provided at least two laser sources arrayed around the powder beam footprint, each providing a different laser beam direction and each laser beam direction satisfying the requirement of an elevation angle of 80° or less and an azimuthal angle of ±60° or less.