Abstract: An extrudable and weldable matrix alloy composite comprising: a) a base material metal of about 50 to 99.9% by weight, b) boron carbide or silicon carbide of about 0.1 to 50% by weight, c) less than about 3.0% by weight of at least one metal having an intermetallic phase temperature lower than the melting point of the base material metal, and d) a reinforcement agent of up to about 5% by weight.

Abstract: Apparatus for die casting a shape from a metal matrix composite billet composed essentially of a metal alloy matrix and dispersed ceramic particles, comprising heating means to soften the metal alloy; a horizontal plunger to drive and to compress the billet; a die through which the softened metal matrix and ceramic particles are formed into a shape defined by the interior surface of the die; and cooling means to maintain the temperature of the interior surface of the die at a predetermined temperature.

Abstract: An improved metal matrix composite utilizes boron carbide as a ceramic additive to a base material metal. The base material metal is aluminum, magnesium, or titanium, or an alloy thereof, provided in powder form with the balance of the material comprising various trace metals such as chromium, copper, iron, magnesium, silicon, titanium, and zinc. The boron carbide powder comprises 10 to 30% by weight of the metal matrix composition. There is at least one other metal additive. The compositions are useful in a variety of applications where lightweight, strength, stiffness, hardness, and low density are desirable. The compositions are extrudable and weldable.

Abstract: A rigid disk substrate for a magnetic recording disk is formed of a ceramic-metal matrix composite. The ceramic-metal matrix composite has a composition ranging from approximately 1 to 40 weight % of ceramic material and 60 to 99 weight % of aluminum or aluminum alloy metal matrix. The ceramic material may be silicon carbide, aluminum oxide, boron carbide, magnesium oxide, silicon oxide, silicon nitride, zirconium oxide, beryllium oxide, titanium boride, titanium carbide, tungsten carbide, or combinations thereof.

Abstract: An improved soluble core for die casting metals or metal matrix composites is formed of a mixture of salt and about more than 0 weight % and less than 20 weight % of ceramic material blended together to produce a homogeneous mixture and compacted under pressure to produce a soluble core having little or no porosity. The ceramic material can be in the form of fibers, particulates, whiskers, and/or platelets, and has a melting temperature greater than that of the salt. The core can include a thermally insulating outer ceramic coating to enable the core to withstand higher die casting temperatures than conventional salt cores. The improved soluble core is removable with hot water and/or steam and the core material can be reclaimed for reuse.

Abstract: A rigid disk substrate for a magnetic recording disk is formed of a metal-clad ceramic-metal matrix composite sandwich structure. The ceramic-metal matrix composite has a composition ranging from approximately 1 to 40 weight % of ceramic and 60 to 99 weight % of metal matrix. The metal matrix material and the metal cladding material are aluminum or an aluminum alloy. The substrate has a thickness less than 1 mm.

Abstract: A Billet formed of an aluminum alloy matrix and ceramic particles is heated in an oxygen-containing atmosphere, forming an aluminum oxide surface and softening the matrix alloy. The semi-solid billet then is compressed in a die casting sleeve and the softened matrix material is displaced into a die to form the shape.

Abstract: An improved soluble core for die casting metals or metal matrix composites is formed of a mixture of salt and up to about 20 weight % of ceramic material blended together to produce a homogeneous mixture and compacted under pressure to produce a soluble core having little or no porosity. The ceramic material can be in the form of fibers, particulates, whiskers, and/or platelets, and has a melting temperature greater than that of the salt. The core can include a thermally insulating outer ceramic coating to enable the core to withstand higher die casting temperatures than conventional salt cores. The improved soluble core is removable with hot water and/or steam and the core material can be reclaimed for reuse. The process is used to form hollow articles.

Abstract: A method of extruding a boron carbide-aluminum alloy metal matrix composite includes heating the ingots of the composite to temperatures of about 570.degree. C., holding the ingots at about 570.degree. C. to soften the ingots, placing the ingots in a heated extrusion chamber, and extruding the softened ingots at pressures about 15% to 20% higher than typical pressures used to extrude aluminum alloys. A method of casting a boron carbide-aluminum alloy metal matrix composite includes heating ingots of the composite to about 700.degree. C. to melt the ingots, gently stirring the melt, removing dross from the melt, vigorously stirring the melt with an impeller without creating a vortex, degassing the melt with an argon diffuser wand, and continuously removing froth formed during degassing until the rate of froth formation is reduced and the melt gently bubbles.

Abstract: A rigid disk substrate for a magnetic recording disk is formed of a boron carbide-metal matrix composite having a density ranging from 2.5 to 2.8 g/cm.sup.3 and a composition ranging from approximately 1 to 40 weight % of boron carbide and 60 to 99 weight % of metal matrix. The substrate has a thickness less than 1 mm and exhibits negligible resonance characteristics at rotation speeds ranging from 0 through 12,000 rpm. The metal matrix is aluminum or an aluminum alloy. The boron carbide includes metal elements added to improve the chelating properties of the metal matrix material by forming intermetallic bonds with the metal matrix material.

Abstract: A neutron shield is formed of a boron carbide-metal matrix composite having a density ranging from 2.5 to 2.8 g/cm.sup.3 and a composition ranging from approximately 10 to 60 weight % of boron carbide and 40 to 90 weight % of metal matrix. The metal matrix is aluminum, magnesium, titanium, or gadolinium or one of their alloys. The boron carbide includes one or more metal elements added to improve the chelating properties of the metal matrix material by forming intermetallic bonds with the metal matrix material. The metal additives are present in the composite in an amount less than approximately 6% by weight. The shield may be in container or plate form.

Abstract: An improved metal matrix composite which, in a preferred embodiment disclosed herein, utilizes boron carbide as the ceramic additive to a base material metal. The metal matrix composite of the present invention begins with the preparation of the boron carbide powder by particle size selection in a jet mill. The resulting powder and metal powder are then mixed by blending of powder of all the various elements such as by means of a conventional blender to uniformly mix powdered substances and avoid stratification and settling. After the particles have been sufficiently mixed, they are degassed and then placed into a die and then into a cylindrical container where the particulates are subjected to extremely high pressures transforming the elements into a solid ingot. It is from these ingots that the extrusion tubes or other articles of manufacture may then be made.

Abstract: An improved metal matrix composite which, in a preferred embodiment disclosed herein, utilizes boron carbide as the ceramic additive to a base material metal. The metal matrix composite of the present invention begins with the preparation of the boron carbide powder by particle size selection in a jet mill. The resulting powder and metal powder are then mixed by blending of powder of all the various elements such as by means of a conventional blender to uniformly mix powdered substances and avoid stratification and settling. After the particles have been sufficiently mixed, they are degassed and then placed into a die and then into a cylindrical container where the particulates are subjected to extremely high pressures transforming the elements into a solid ingot.

Abstract: An improved metal matrix composite which, in a preferred embodiment disclosed herein, utilizes boron carbide as the ceramic additive to a base material metal. The metal matrix composite of the present invention begins with the preparation of the boron carbide powder by particle size selection in a jet mill. The resulting powder and metal powder are then mixed by blending of powder of all the various elements such as by means of a conventional blender to uniformly mix powdered substances and avoid stratification and settling. After the particles have been sufficiently mixed, they are degassed and then placed into a die and then into a cylindrical container where the particulates are subjected to extremely high pressures transforming the elements into a solid ingot. It is from these ingots that the extrusion tubes or other articles of manufacture may then be made.