Cutting elements for earth-boring tools may include a superhard, polycrystalline material and a substrate adjacent to and secured to the superhard, polycrystalline material at an interface. The substrate may include a first region exhibiting a first coefficient of thermal expansion and a second region exhibiting a second, different coefficient of thermal expansion. The first region may be spaced from the superhard, polycrystalline material. The second region may extend from laterally adjacent to at least a portion of the first region to longitudinally between the first region and the superhard, polycrystalline material.

Cutting elements for earth-boring tools may include a superhard, polycrystalline material and a substrate adjacent to and secured to the superhard, polycrystalline material at an interface. The substrate may include a first region exhibiting a first coefficient of thermal expansion and a second region exhibiting a second, different coefficient of thermal expansion. The first region may be spaced from the superhard, polycrystalline material. The second region may extend from laterally adjacent to at least a portion of the first region to longitudinally between the first region and the superhard, polycrystalline material.

A metal matrix composite tool that includes a hard composite portion comprising a reinforcement material infiltrated with a binder material, wherein the reinforcement material comprises a refractory metal component dispersed with reinforcing particles, wherein a surface roughness of the reinforcing particles is at least two times greater than the refractory metal component, wherein the refractory metal component has a failure strain of at least 0.05 and a shear modulus of 200 GPa or less, and wherein the reinforcing particles have a failure strain of 0.01 or less but at least five times less than the failure strain of the refractory metal component, and the reinforcing particles have a shear modulus of greater than 200 GPa and at least two times greater than the shear modulus of the refractory metal component. The reinforcing particles may comprise an intermetallic, a boride, a carbide, a nitride, an oxide, a ceramic, and/or a diamond.

A metal matrix composite tool that includes a hard composite portion comprising a reinforcement material infiltrated with a binder material, wherein the reinforcement material comprises a refractory metal component dispersed with reinforcing particles, wherein a surface roughness of the reinforcing particles is at least two times greater than the refractory metal component, wherein the refractory metal component has a failure strain of at least 0.05 and a shear modulus of 200 GPa or less, and wherein the reinforcing particles have a failure strain of 0.01 or less but at least five times less than the failure strain of the refractory metal component, and the reinforcing particles have a shear modulus of greater than 200 GPa and at least two times greater than the shear modulus of the refractory metal component. The reinforcing particles may comprise an intermetallic, a boride, a carbide, a nitride, an oxide, a ceramic, and/or a diamond.

The invention relates to an insert for an attack tool, the insert comprising a super-hard cap having a volume and bonded to a substrate at an interface, the super-hard cap having an average Young's modulus of greater than 900 GPa and the substrate characterized in that it comprises a reinforcing bolster portion as a means for stiffening a region of the substrate proximate the interface, the reinforcing bolster portion having an aggregate volume that is greater than that of the super-hard cap and an average Young's modulus at least 60% that of the super-hard cap. The invention further relates to a method for manufacturing such an insert and a method for using such an insert.

The invention relates to an insert for an attack tool, the insert comprising a super-hard cap having a volume and bonded to a substrate at an interface, the super-hard cap having an average Young's modulus of greater than 900 GPa and the substrate characterized in that it comprises a reinforcing bolster portion as a means for stiffening a region of the substrate proximate the interface, the reinforcing bolster portion having an aggregate volume that is greater than that of the super-hard cap and an average Young's modulus at least 60% that of the super-hard cap. The invention further relates to a method for manufacturing such an insert and a method for using such an insert.

A centrifugally cast composite metal product having an axis of rotational symmetry and a mass of at least 5 kg, comprises a host metal and insoluble solid refractory particles of & refractory material in a non-uniform distribution throughout the host metal. The particles have a density that is within 30% of the density of the host metal at its casting temperature.

The present invention relates to a coated cutting tool including a Cr-containing cemented carbide substrate having WC, a binder phase and a gamma phase. The cemented carbide includes a gradient surface zone with a thickness of between 2 to 100 m, which is binder phase enriched and depleted of gamma phase. The cemented carbide includes M.sub.7C.sub.3 carbides in an amount of between 0.5 to 7 area % measured in the bulk, where M is elements being Cr, W and at least one binder metal. The coated cutting inserts shows an improved edge line toughness.

The present invention relates to a coated cutting tool including a Cr-containing cemented carbide substrate having WC, a binder phase and a gamma phase. The cemented carbide includes a gradient surface zone with a thickness of between 2 to 100 m, which is binder phase enriched and depleted of gamma phase. The cemented carbide includes M.sub.7C.sub.3 carbides in an amount of between 0.5 to 7 area % measured in the bulk, where M is elements being Cr, W and at least one binder metal. The coated cutting inserts shows an improved edge line toughness.

A method of treating a cemented carbide insert for rock drilling and mineral cutting is provided. The insert includes a core of cemented carbide and a surface zone of cemented carbide, wherein the core further contains eta-phase and the surface zone is free of eta-phase. The mining insert is subjected to a surface hardening process, wherein the surface hardening process is executed at an elevated temperature of or above 50 C.