Other

Cornelius Phaal

Richard P Burnand

Henry B Dyer

Noel J Pipkin

Moosa M Adia

Douglas J Reid

Nicholas Mastrantonis

Rainer Dietrich

Nicoll A Campbell

Patrick A Seeber

Richard P Brunand

An abrasive compact is provided which has a plurality of recesses which may take the form of grooves or holes formed in a major surface thereof. The recesses contain no solid material and serve as crack arrester formations.

Abrasive compacts

A wire drawing die blank is produced by providing an abrasive compact core, having top and bottom surfaces and a side surface, depositing a thin layer of high melting metal such as nickel, iron, chromium or cobalt on the side surface, the coating substantially following the contour of the side surface, providing a support having a hole extending therethrough, the hole having a cross-section larger than that of the core and allowing for the core to be located therein, locating the core in the hole leaving a space between the metal coating and the support, introducing a suitable braze, preferably in liquid form, in the space and causing the braze to bond the core to the support.

Wire drawing die

A tool insert comprising an abrasive compact bonded to a cemented carbide support. The cutting edge of the tool is provided by the periphery of the compact. A plurality of circular, concentric recesses, each filled with abrasive compact material, extend into the cemented carbide support from the compact/carbide interface.

Abrasive product

A thermally stable diamond compact is bonded to a cemented carbide substrate through a nickel bonding layer. Bonding takes place under elevated conditions of temperature and pressure where the temperature is at least 1000.degree. C. and the pressure is at least 30 kilobars.

Thermally stable diamond abrasive compact body

A tool component is provided which comprises an abrasive compact bonded to a cemented carbide support body. The abrasive compact has two zones which are joined by an interlocking, common boundary. The one zone provides the cutting edge or point for the tool component while the other zone is bonded to the cemented carbide support body. In use, the tool component is so located in the working surface of the tool that the lower zone is partially embedded in that surface. The interlocking, common boundary is located above the working surface.

Tool component

The invention provides a composite diamond abrasive compact comprising a thermally stable diamond compact directly bonded to a cemented carbide substrate. The thermally stable diamond compact comprises bonded diamond forming a coherent, skeletal mass and a second phase which preferably consists of silicon and/or silicon carbide. A method of producing the composite diamond abrasive compact under controlled elevated temperature and pressure conditions is also provided.

A method is provided of making a drill blank comprising a cylindrical carbide body 24 having a vein 26 of an abrasive compact embedded in one end thereof and bonded to the carbide. A method involves the steps of providing a solid, cylindrical body 10 of cemented carbide, forming a series of grooves 12 in one end surface 14 thereof, placing compact forming material in the grooves, exposing the cylindrical body to temperature and pressure conditions suitable to produce an abrasive compact of the material in the grooves, and severing the cylindrical body from one end surface 14 to the opposite end surface 20 to produce a plurality of the drill blanks.

Drill blanks

A plurality of blanks for drill bits are produced from a disc-shaped composite abrasive compact by first producing a plurality of sticks of polygonal shape end-on and thereafter longitudinally rounding each stick. The rounded drill blank is then fluted to produce a small diameter twist drill bit.

Method of making a blank of a drill bit

A method of making aggregated diamond abrasive particles comprising forming a mixture of diamond abrasive particles and a powdered metal, heating the mixture to sinter the metal followed by cooling to produce a mass and crushing the mass to obtain the aggregated particles, characterized in that the particles are selected from Types A, B and C, as hereinafter defined, and mixtures thereof:

Abrasive materials

An abrasive body is provided which has high strength and an ability to withstand high temperatures making it suitable as a tool insert for dressing tools and surface set drill bits. The body comprises a mass of diamond particles present in an amount of 80 to 90 percent by volume of the body and a second phase present in an amount of 10 to 20 percent by volume of the body, the mass of diamond particles containing substantial diamond-to-diamond bonding to form a coherent skeletal mass and the second phase containing nickel and silicon, the nickel being in the form of nickel and/or nickel silicide and the silicon being in the form of silicon, silicon carbide and/or nickel silicide. The abrasive bodies are made under conditions of elevated temperature and pressure suitable for diamond compact manufacture.

Abrasive product and method for manufacturing

A tool component comprising a composite compact located in a sloping recess in one end of a solid, elongate right-circular cylindrical pin and bonded thereto. The recess is characterized in that it is formed in the pin to one side of a longitudinal plane passing through the central axis of the pin and the base wall of the recess slopes from one end surface towards a side surface. Bonding of the composite compact to the pin is preferably achieved by means of a braze alloy having a working temperature of less than 700.degree. C. and containing silver, copper, zinc, manganese and nickel. The tool component has particular application as a cutting component for a drill bit.

A method of making inserts suitable for tool or drill bits which includes the step of fragmenting, e.g. by means of a laser beam, an abrasive compact in a plurality of discrete, non-segmental fragments. The inserts may have a variety of shapes, some of which are new, such as conical, truncated conical or truncated pyrimidal. The inserts are particularly useful for wire-drawing die blanks and core or oil-well drill bits.

Method of making tool inserts and drill bits

A method of making aggregated diamond abrasive particles comprising forming a mixture of diamond abrasive particles and a powdered metal, heating the mixture to sinter the metal followed by cooling to produce a mass and crushing the mass to obtain the aggregated particles, characterized in that the particles are selected from Types A, B and C, as hereinafter defined, and mixtures thereof: Particles of Type A have the following characteristics:

Method of making sintered metal-diamond aggregates

An abrasive body, typically in the form of a cylinder, comprising an abrasive compact and a core of high rigidity material such as cemented carbide embedded in to the compact, the compact comprising a mass of abrasive particles such as diamond or cubic boron nitride particles, present in an amount of at least 70 percent by volume of the compact, bonded into a hard conglomerate and the body of high rigidity material being located inside the side surface of the compact and extending from the top surface to the bottom surface of the compact.

Abrasive compact with a core of high rigidity material

The invention provides a method of making an abrasive product, e.g. a grinding wheel rim, which consists in providing a mixture of needle-shaped abrasive particles and the starter ingredients for a bonding matrix, causing the mixture to flow, preferably in a passage having a constriction, so causing the particles to orientate with their long axes substantially in the direction of flow, and allowing the mixture to set, at least partially.

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Johannesburg, Transvaal, South Africa

Cornelius Phaal