Abstract: A particle-matrix composite material comprises a metal alloy phase, the metal alloy having a resistivity of at least about seven hundred and fifty (750) nano-ohms per meter, and a composite phase comprising ceramic particles dispersed throughout portions of the metal alloy phase. The composite phase extends throughout the particle-matrix composite material in a substantially three-dimensional network, and regions of the composite phase at least partially surround regions of the metal alloy phase that are free of the ceramic particles. Methods of forming a particle-matrix composite body include coating particles of metal alloy with relatively finer particles of ceramic, partially compacting the coated particles of metal alloy, and heating the partially compacted particles of metal alloy to form a substantially continuous metal alloy matrix with ceramic particles dispersed therein. Downhole tools including components comprising particle-matrix composite materials are also disclosed.