Methods of forming larger sintered compacts of PCD and other sintered ultrahard materials are disclosed. Improved solvent metal compositions and layering of the un-sintered construct allow for sintering of thicker and larger high quality sintered compacts. Jewelry may also be made from sintered ultrahard materials including diamond, carbides, and boron nitrides. Increased biocompatibility is achieved through use of a sintering metal containing tin. Methods of sintering perform shapes are provided.

An ultrasonic knife has a cutting portion formed with at least one cutting edge and a fastening portion. The fastening portion has an external thread for connection to a sonotrode. The cutting portion and the fastening portion are formed in one piece from cemented carbide material. The cemented carbide material includes hard particles that are, at least predominantly, formed by tungsten carbide and a metallic binder. The external thread of the fastening portion has a thread pitch p and is shaped such that the root of the thread turns has a rounded shape with a root radius R of 0.2*p≤R≤0.3*p.

A cemented carbide includes a first hard phase and a binder phase. The first hard phase is composed of tungsten carbide grains. The binder phase includes cobalt and nickel as constituent elements. An arbitrary surface or arbitrary cross section of the cemented carbide has: a region R1 interposed between an interface between the tungsten carbide grains and the binder phase and an imaginary line A; a region R2 interposed between the imaginary line A and an imaginary line B; and a region R3 other than the region R1 and R2. When a line analysis is performed in a range including the region R1 and the region R3 adjacent to the region R1 with the region R2, a ratio C.sub.5/C.sub.20 of a maximum atomic concentration C.sub.5 at % of cobalt in the region R1 and a maximum atomic concentration C.sub.20 at % of cobalt in the region R3 is more than 1.

A cemented carbide includes a first hard phase and a binder phase. The first hard phase is composed of tungsten carbide grains. The binder phase includes cobalt and nickel as constituent elements. An arbitrary surface or arbitrary cross section of the cemented carbide has: a region R1 interposed between an interface between the tungsten carbide grains and the binder phase and an imaginary line A; a region R2 interposed between the imaginary line A and an imaginary line B; and a region R3 other than the region R1 and R2. When a line analysis is performed in a range including the region R1 and the region R3 adjacent to the region R1 with the region R2, a ratio C.sub.5/C.sub.20 of a maximum atomic concentration C.sub.5 at % of cobalt in the region R1 and a maximum atomic concentration C.sub.20 at % of cobalt in the region R3 is more than 1.

A composite composed of one or a plurality of principal strengthening compounds and at least one principal cemented refractory metal that is prepared by combining a suitable binary to senary borides and/or carbides with a unitary to binary principal refractory metal is disclosed. As compared with the conventional sintered cemented carbides, the composite of the disclosure not only possess high hardness and high toughness but also has various ratios of principal components since it is not prepared with equal mole during the process.

A method of forming a cutting element comprises forming a first material comprising discrete coated particles within a container. The first material is pressed to form a first green structure comprising interbonded coated particles. A second material comprising additional discrete coated particles is formed over the first green structure within the container. The second material is pressed to form a second green structure comprising additional interbonded coated particles. The first green structure and the second green structure are sintered to form a multi-layered cutting table. Additional methods of forming a cutting element, a cutting element, and an earth-boring tool are also described.

A method of forming a supporting substrate for a cutting element comprises forming a precursor composition comprising discrete WC particles, a binding agent, and discrete particles comprising Co, one or more of Al, Be, Ga, Ge, Si, and Sn, and one or more of C and W. The precursor composition is subjected to a consolidation process to form a consolidated structure including WC particles dispersed in a homogenized binder comprising Co, W, C, and one or more of Al, Be, Ga, Ge, Si, and Sn. A method of forming a cutting element, a cutting element, a related structure, and an earth-boring tool are also described.

A sintered composite material obtainable by a method which includes providing a composition which includes at least one hardness carrier and a base binder alloy, and sintering the composition. The base binder alloy includes from 66 to 93 wt.-% of nickel, from 7 to 34 wt.-% of iron, from 0 to 9 wt.-% of cobalt, and up to 30 wt.-% of one or more elements selected from W, Mo, Cr, V, Ta, Nb, Ti, Zr, Hf, Re, Ru, Al, Mn, B, N and C. The wt.-% proportions of the base binder alloy add up to 100 wt.-%.

There is provided a powder material that is for densifying a molded article manufactured by an additive layer manufacturing method and improving harness of the molded article. There is provided a powder material for use in additive layer manufacturing containing ceramics and metals, in which a tapped filling rate defined by (tapped density/theoretical density)×100% is 40% or more.

Provided is a corrosion, erosion and wear resistant cemented carbide for high demand applications including, for example, use as a component within oil and gas production. The cemented carbide includes a hard phase and a binder phase. The cemented carbide may include, for example. Ni, Cr and Mo. The binder phase content of the cemented carbide is between 7 to 11 wt %. The WC of the cemented carbide may have an average grain size of from 0.1 to 2 μm.