Laminated and composite impregnated cutting structures for drill bits

A laminated cutting element for use on a rotary-type earth-boring drill bit for drilling subterranean formations preferably including at least one first segment formed of a hard, continuous-phase material impregnated with a particulate superabrasive material laminated to and including at least one second segment formed of a continuous-phase material having essentially no particulate superabrasive material impregnated therein. Alternatively, the at least one second segment may have superabrasive and/or abrasive material impregnated therein which is less abrasive than the superabrasive material impregnated in the at least one first segment. Preferably, the continuous-phase material in which the at least one first segment and the at least one second segment are made is a metal matrix material.A further alternative of the present invention includes a single segment formed of a continuous-phase material in which a particulate superabrasive material is impregnated. The alternative single segment has a relatively thin cross-sectional thickness and is securable to a support member preferably fabricated from a tough and ductile material. The support member further includes a bit attachment portion securable to a bit body and a segment-receiving portion adapted to receive and support the superabrasive impregnated segment during drilling.A yet further alternative of the present invention includes a composite segment formed of a continuous-phase material wherein a preselected portion of the segment is impregnated with a particulate superabrasive material.