A cBN sintered compact comprises: cubic boron nitride grains and a binder phase, wherein 1) the binder phase comprises a TiAl alloy containing at least one element selected from the group consisting of Si, Mg, and Zn, and further comprises Ti.sub.2CN and TiB.sub.2; 2) the ratio I.sub.Ti2CN/I.sub.Ti-Al in XRD is 2.0 or more and 30.0 or less where I.sub.Ti2CN represents the peak intensity of Ti.sub.2CN appearing at 2? angle from 41.9? to 42.2? and I.sub.Ti-Al represents the peak intensity of the TiAl alloy at 2? angle from 39.0? to 39.3?; 3) areas where Ti and B elements overlap have an average aspect ratio of 1.7 or more and 6.5 or less and an area rate of 0.025% or more and 0.120% or less, in a mapping image of the Ti and B elements by Auger electron spectroscopy.

A cutting tool includes a supporting body and a cBN or PCD cutting edge tip attached to the supporting body via a 5-150 ?m braze joint. The supporting body is cemented carbide having 3-25 wt % of a metallic binder, optionally up to 25 wt % of carbides or carbonitrides of one or more elements of group 4, 5, or 6, and the rest WC. The metallic binder includes at least 40 wt % Ni, and the braze joint has, in the order from the supporting body, a first layer of TiC situated next thereto, with an average thickness of 10-400 nm, a second layer, with an average thickness of 0.5-8 ?m, having in average at least 5 wt % metallic Ni, in average 25-60 wt % metallic Cu and in average 15-45 wt % metallic Ti, and a third layer, with an average thickness of 4-145 ?m, having metallic Ag and metallic Cu.

A cutting tool includes a supporting body and a cBN or PCD cutting edge tip attached to the supporting body via a 5-150 ?m braze joint. The supporting body is cemented carbide having 3-25 wt % of a metallic binder, optionally up to 25 wt % of carbides or carbonitrides of one or more elements of group 4, 5, or 6, and the rest WC. The metallic binder includes at least 40 wt % Ni, and the braze joint has, in the order from the supporting body, a first layer of TiC situated next thereto, with an average thickness of 10-400 nm, a second layer, with an average thickness of 0.5-8 ?m, having in average at least 5 wt % metallic Ni, in average 25-60 wt % metallic Cu and in average 15-45 wt % metallic Ti, and a third layer, with an average thickness of 4-145 ?m, having metallic Ag and metallic Cu.

A method for treating a super-hard structure, the method including heating the super-hard structure to a treatment temperature of at least 500 degrees centigrade and cooling the super-hard structure from the treatment temperature to a temperature of less than 200 degrees centigrade at a mean cooling rate of at least 1 degree centigrade per second and at most 100 degrees centigrade per second to provide a treated super-hard structure. A PCBN structure produced by the method may have flexural strength of at least 650 MPa.

A hard material which, when used as a material of a sintered material, makes it possible to obtain a sintered material with excellent abrasion resistance, a sintered material, a cutting tool including the sintered material, a method for manufacturing the hard material and a method for manufacturing the sintered material are provided. The hard material contains aluminum, nitrogen, and at least one element selected from the group consisting of titanium, chromium, and silicon, and has a cubic rock salt structure.

An object is to prolong the life of a cubic boron nitride cutting tool used for cutting a heat-resistant alloy. A cubic boron nitride cutting tool includes an edge tip made of a sintered cubic boron nitride compact having a thermal conductivity within the range of 20 to 70 W/m.Math.K and including cubic boron nitride particles having an average particle diameter within the range of 0.5 m to 2 m; and a base metal that holds the edge tip at a corner portion of the base metal, wherein a cutting edge formed on the edge tip of the tool has a positive rake angle.

A cubic boron nitride sintered material includes cubic boron nitride and a binder. The binder includes a first material and a second material. The first material is one or two or more first chemical species each including at least one first metallic element selected from the group consisting of tungsten, cobalt, and aluminum. Each of the first chemical species is a metal, an alloy, an intermetallic compound, a compound, or a solid solution. The second material is one or two or more second chemical species each including at least one second metallic element selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, and chromium. Each of the second chemical species is a solid solution derived from at least one selected from the group consisting of nitride, carbide, and carbonitride. In each of the second chemical species, 0.1 atom % to 10 atom % of aluminum is dissolved.

A cBN sintered body contains cBN particles whose proportion is 85-97% by volume, and a binding phase whose proportion is 3-15% by volume. The cBN sintered body contains Al whose ratio to the entirety of the cBN sintered body is 0.1-5% by mass, and Co whose mass ratio to the Al is 3 to 40, and includes Al.sub.3B.sub.6Co.sub.20.

The hard coating layer includes at least a complex nitride or complex carbonitride layer expressed by the composition formula (Ti.sub.1-xAl.sub.x)(C.sub.yN.sub.1-y). The average Al content ratio x.sub.avg the average C content ratio y.sub.avg satisfy 0.60x.sub.avg0.95 and 0y.sub.avg0.005, respectively, each of the x.sub.avg and y.sub.avg is in atomic ratio. The crystal grains constituting the complex nitride or complex carbonitride layer include a crystal grain having the NaCl face-centered cubic structure. A predetermined average crystal grain misorientation exists in the crystal grains having the NaCl face-centered cubic structure.

A method of making a super-hard article comprising a super-hard structure (14) bonded to a substrate (18), the super-hard structure comprising a sintered plurality of super-hard grains. The method includes providing raw material powder suitable for sintering the super-hard structure. The raw material powder is combined with organic binder material in a liquid medium to form paste. The content of the raw material powder is more than 60 and less than 85 mass per cent of the paste and the composition of the paste is such that it has a shear rate of at most 25 inverse second (s-.sup.1). A substrate assembly is provided, which comprises the substrate, having a formation surface area configured for forming a boundary of the super-hard structure, the substrate comprising a recess coterminous with the formation surface area. The paste is extruded into contact with the formation surface area to provide a paste assembly. The paste assembly is heat treated to remove the binder material and provide a pre-sinter assembly. The pre-sinter assembly is subjected to a pressure and temperature sufficient to sinter the raw material powder and transform it into the super-hard structure bonded to the substrate at a boundary coterminous with the formation surface area. The super-hard material is diamond or cubic boron nitride.