Method of forming hard facings on materials

A method for applying a hard facing along an edge of a relatively soft substrate, said method comprising:

• rotatably supporting a member of relatively hard material for forming the hard facing, said member having an end face and a rotation axis that passes through the end face;
• rotating the member of relatively hard material while pressing its end face against a substrate during an initial touchdown phase;
• progressively increasing pressure applied by said member of relatively hard material during said initial touchdown phase so as to cause an interface at which heat is generated by friction to move from a position in contact with said substrate to a position along the rotating member spaced at least 0.2 mm from the substrate;
• maintaining rotation of said member of relatively hard material while pressing its end face against a relatively soft substrate and bringing about relative translational movement between said member and the relatively soft substrate so that said member moves along the edge of the relatively soft substrate, whereby the relatively hard material is deposited along the edge of the relatively soft substrate by rotatory friction surfacing, the pressure, rate of rotation of said member and rate of relative translational movement between said member and the relatively soft substrate being such that the interface at which heat is generated by friction is maintained at a position spaced at least 0.2 mm from the relative soft substrate so as to deposit on the relative soft substrate a homogeneous layer of the relatively hard material greater than 0.2 mm thick.

A method for applying a hard facing along an edge of a relatively soft substrate, said method comprising:

• supporting in end to end abutting relationship a start plate, a relatively soft substrate and an end plate;
• rotatably supporting a member of relatively hard material for forming the hard facing, said member having an end face and a rotation axis that passes through said end face;
• rotating said member of relatively hard material while pressing its end face against the start plate and bringing about relative translational movement between said member and the start plate so that said member moves along the start plate and the relatively hard material is deposited along the start plate by rotary friction surfacing, the pressure being progressively increased and the rate of rotation of said member and rate of relative translational movement between said member and the start plate being such than an interface at which heat is generated by friction has moved from a position in contact with the start plate to a position along the rotating member spaced at least 0.2 mm from the start plate no later than when said member of relatively hard material reaches an edge of the start plate abutting the relative soft substrate;
• maintaining rotation of said member of relatively hard material while pressing its end face against the relative soft substrate and bringing about relative translational movement between said member and the relative soft substrate so that said member moves along the edge of the relative soft substrate, whereby the relatively hard material is deposited along the edge of the relative soft substrate by rotary friction surfacing, the pressure, rate of rotation of said member and rate of relative translational movement between said member and the relative soft substrate being such that the interface at which heat is generated is maintained at a substantially constant distance along the rotating member spaced from the relatively soft substrate so as to deposit on the relative soft substrate a homogeneous layer of the relatively hard material greater than 0.2 mm thick;
• and maintaining contact between said member of relatively hard material and the relatively soft substrate until said member has passed onto the end plate.