Earth-boring tools having particle-matrix composite bodies and methods for welding particle-matrix composite bodies

A method of joining a particle-matrix composite body of an earth-boring tool to a metallic body, the method comprising:

• forming a joint along an interface between a particle-matrix composite body of the earth-boring tool and a metallic body of the earth-boring tool, comprising:
• forming a first bevel portion and a second bevel portion on a face portion of each of the particle-matrix composite body and the metallic body to form a weld groove disposed along the interface between the particle-matrix composite body and the metallic body;
• and
• forming an overlapping interface at least proximate a root portion of the weld groove;
• heating a volume of the particle-matrix composite body proximate the weld groove to an elevated first temperature below the melting temperature of a matrix material of the particle-matrix composite body;
• heating at least a portion of the volume of the particle-matrix composite body proximate the weld groove with a welding torch to a second temperature greater than the melting temperature of the matrix material of the particle-matrix composite body;
• melting a metallic filler material;
• forming a weld bead within the weld groove to weld the metallic filler to the particle-matrix composite body and to the metallic body at the joint, wherein forming a weld bead comprises:
• forming a first weld bead along an interface within the weld groove by maintaining the transverse location of the welding torch relative to the interface while passing the torch along the interface;
• and
• forming additional weld beads by transversely oscillating the welding torch relative to the interface in a flat-topped saw tooth weave pattern while passing the torch along the interface;
• providing the welded particle-matrix composite body, metallic filler material and metallic body at a third temperature;
• and
• cooling the welded particle-matrix composite body, metallic filler material and metallic body at a controlled rate.