摘要:
A composite body includes 5 to 40% by mass of SiC whiskers and/or up to 80% by mass SiC lamellae and/or of up to 75% by mass SiC powder, 0.05 to 3% by mass of at least one component selected from the group of Y.sub.2 O.sub.3, SiO.sub.3, MgO, NiO and AlN and/or up to 40% by mass of at least one compound selected from the group of carbides, nitrides or carbonitrides of a metal from one of the Groups IVa, Va, Via of the Periodic Table of elements, and/or up to 40% by mass of at least one oxide of at least one metal selected from the group which consists of the metals of Group IVa of the Periodic Table of elements, 0.05 to 10% by mass of a metal constituent selected from the group which consists of at least one element selected from the group including nickel, cobalt and iron, and of the group which consists of chromium in an amount up to 25% of the mass of the metal constituent with the balance being at least one element selected from the group which consists of nickel, cobalt and iron, and a minimum of 30% by mass Al.sub.2 O.sub.3 to the balance of the body.
摘要:
The invention relates to a composite hard metal body of hard material, a binder and embedded reinforcing material, as well as to a process for the production of the composite hard metal body by methods of powder metallurgy.In order to create a composite hard metal body with improved toughness under load, improved hardness and a lower fracture susceptibility, the invention proposes to build in monocrystalline, preferably needle-shaped and/or platelet-shaped reinforcing materials, coated with an inert layer with respect to the binder metal phase and consisting of borides and/or carbides, and/or nitrides and/or carbonitrides of the elements of Groups IVa or Va or mixtures thereof and/or coated monocrystalline reinforcing material of SiC, Si.sub.3 N.sub.4, Si.sub.2 N.sub.2 O, Al.sub.2 O.sub.3, ZrO.sub.2, AlN and/or BN.The composite hard metal body is produced by powder-metallurgical methods, whereby the reinforcing material in a deagglomerated and graded state, optionally coated by CVD or PVD with a layer which is inert with respect to the binder metal phase, is blended with the ground mixture of hard materials and binder, dried, granulated, uniaxially pressed or isostatically pressed at low temperatures and then the composite body is produced by sintering, respectively a combined or separate sintering/HIP-process or through axial hot-pressing. The axial hot-pressing is preferred in cases where the reinforcing material surpasses 20% by volume, under this level the other mentioned processes are preferred.
摘要:
In order to improve the toughness characteristics of a cermet alloy, while retaining high resistance to wear, a composition is disclosed which contains 30 to 60% by weight of Ti, 5 to 20% by weight of W, 5 to 15% by weight of Ta, in which up to 70% of the Ta can be replaced by Nb, and 5 to 25% by weight of Ni and/or Co binder with more than 80 mole %, relative to the above transition elements of carbon and nitrogen. The composition is prepared by grinding, compressing and sintering a solid, powder-form mixture containing (Ti,W,Ta,Nb)C powder, Ti(C,N) powder, and WC powder, each powder having a particle size
摘要:
The invention relates to a hard-metal body whose hard-metal phase consist of tungsten carbide and whose binder metal phase consists of nickel and chrome.Especially for the enhancement of the corrosion resistance it is proposed that the hard metal contain also TiN in addition to the hard-metal phase, whereby the content of TiN and and binder metal phase amounts to 5 to 25% by mass and is composed by 0.1 to 10% by mass TiN, 5 to 15% by mass chrome, the balance being made up by nickel.
摘要:
The invention concerns composites substantially consisting of: a cermet material having a binder metal phase of between 5 and 30 mass % and the remainder comprising at least one carbon nitride phase; or a hard metal with a hard material phase of between 70 and 100 %, the remainder being a binder metal phase, with the exception of a WC-Co hard metal, with up to 25 mass % cobalt as binder metal; or a powder-metallurgically produced steel. The invention further concerns a process for producing this composite. In order to improve bending strength and hardness, sintering is carried out in a microwave field.
摘要:
A sintered hard metal body having improved heat resistance and higher cutting performance is produced by a process including mixing together at least one hard substance, at least one binder material, and at least one of at least one complex carbide and at least one complex nitride to form a starting mixture each constituent of which is in powdered form. The at least one hard substance is selected from the group consisting of carbides, nitrides, and carbonitrides of transition metals of Groups IVB, VB and VIB of the Periodic Table of Elements, is present as at least one of a carbide, a mixed carbide, a nitride, a mixed nitride, a carbonitride, and a mixed carbonitride, and has a cubic crystal form. The at least one binder metal is selected from the group including iron, nickel and cobalt. The starting mixture is then ground and compressed into a predetermined shape, followed by sintering to melt the at least one binder metal and decompose the complex carbide and/or complex nitride to form at least one of at least one transition metal carbide and at least one transition metal nitride which grows on the surface of the at least one hard substance in powdered form and forms a diffusion inhibiting layer thereon.
摘要:
A process for producing a cutting tool includes the steps of subjecting a sintered body to a nitrogen gas pressure treatment conducted under a pressure ranging between 0.2 and 10 MPa and at a temperature between 900.degree. C. to 1300.degree. C. for a period of at least 0.5 hours, evacuating a protective gas at a pressure between 10 Pa and 20 kPa at temperatures between 1000.degree. C. and 1350.degree. C. over more than 0.5 hours before the sintered body is cooled under a pressure between 10 Pa and 0.1 Pa, thereby forming a binding layer and treating a metal base body with CVD or PVD or plasma activated CVD for coating the metal base body with the binding layer.