Abstract: A sintered hardmetal (cemented tungsten carbide) product has a core made of a first grade of cobalt or nickel bonded cemented tungsten carbide with a surface layer of a second grade of distinctively different cobalt or nickel bonded cemented tungsten carbide. The first grade, or core, is generally a relatively tough (impact resistant or shock resistant) grade of cobalt or nickel bonded hardmetal while the surface layer is a relatively hard (wear resistant) grade of cobalt or nickel bonded hardmetal. The surface layer may, however, be designed to provide corrosion resistance or crater resistance to the article. If desired, multiple layers can be provided with gradient layers included between the core and surface layer. Typical uses of such layered composite carbide articles are as tool materials such as cutting tools or cutting tool inserts, mining tools or wear parts of any design typically manufactured in the cemented carbide industry.

Abstract: A method for forming a sintered hard metal composite is provided in which unsintered nodules of a pre-blended hard metal powder of a first grade are uniformly dispersed into unsintered nodules of a pre-blended hard metal composite of a second grade. The pre-blended hard metal powders form a composite powder blend which is subsequently pressed and sintered to form the dispersion alloyed hard metal composite. A sufficient amount of pressing lubricant is provided to one of the pre-blended hard metal powders so that each of the hard metal powders shrinks at approximately the same rate relative to the application of pressure during the compacting process. The pressing lubricant is added to that hard metal powder which shrinks more during sintering.

Abstract: A hard metal composite is formed from a mixture of two or more pre-blended, unsintered hard metal composites in which the properties of each constituent are different. The constituent components are selected so that they have different grain sizes, different binder contents, different metal carbide or binders, or some combination of these. Primarily, the constituents are chosen on the basis of their properties and compatability, and are chosen to utilize the superior properties of one of the constituents without detrimentally affecting the desirable properties of the other. As an example, a pre-blended composite having a superior hardness may be dispersed in a second composite having a superior toughness with the resultant material having a hardness which approaches that of the harder constituent yet maintaining the toughness of the matrix constituent.

Abstract: Tooling and a method are provided for producing powder metal compacts in which a fine hole is provided through the compact without the need for secondary operations. A top punch and bottom punch are used in an opposing relationship and a stem is provided on the top punch to form the hole through the compact. A resilient member is placed upon the bottom punch opposite the stem. When powder metal is introduced into the die cavity of the press, the powder is compressed by pressing the first punch against the second punch. During this powder compaction process, the stem of the first punch will press through the powder until it engages and penetrates the resilient member. When the first punch and second punch are released, a powder metal compact is formed having a hole provided the entire length therethrough. Such a powder metal compact is especially designed for use as a wire-drawing die.