Abstract: Disclosed herein is a method and gas atmosphere for a metal component in a continuous furnace. In one embodiment, the method and gas atmosphere comprises the use of an effective amount, or about 1 to about 10 percent volume of endo-gas, into an atmosphere comprising nitrogen and hydrogen. In another embodiment, there is provided a method sintering metal components in a furnace at a one or more operating temperatures comprising: providing a furnace comprising a belt comprising a wire mesh material wherein the metal components are supported thereupon; and sintering the components in the furnace in an atmosphere comprising nitrogen, hydrogen, and effective amount of endothermic gas at the one or more operating temperatures ranging from about 1800° F. to about 2200° F. wherein the amount of endothermic gas in the atmosphere is such that it is oxidizing to the wire mesh material and reducing to the metal components.

Abstract: Disclosed is a process of producing a porous metal body containing a metal component which is likely to be oxidized, by which process the amounts of residual carbon and residual oxygen therein are decreased, and by which the performance of the product porous body can be largely promoted. The process for producing a porous metal body by sintering a material of the porous metal body, which material is obtained by coating a slurry containing a metal powder and an organic binder on an organic porous aggregate, comprises a defatting step of treating the material of the porous metal body at a temperature not higher than 650° C.

Abstract: A copper graphite composite material suitable for use in applications such as brushes, switches and contact materials for rail systems and other industrial devices. The composite comprises a copper network matrix having a plurality of pores containing graphite. The composite may have an IACS value of at least 40% which may even be higher than 70% and a density value of at least 6.0 g/cm3. The method for preparation of the composite comprises mixing graphite and copper powder under non-oxidising conditions, compacting the mixture and sintering under non-oxidising conditions.

Abstract: The invention relates to bullets having increased frangibility (or which can be easily fragmented) and to materials and processes for the manufacture of such bullets. The bullets of the present invention are typically made from copper or copper alloy powders (including brass, bronze and dispersion strengthened copper) which are pressed and then sintered under conditions so as to obtain bullets with the desired level of frangibility. In preferred embodiments of the invention, the bullets also contain several additives that increase or decrease their frangibility.

Abstract: One or more organic or inorganic metal salts or compounds of at least one of the groups IV, V and VI of the periodic system, particularly V, Cr, Mo and W, optionally together with one or more organic iron group metal salts, are dissolved in at least one polar solvent and complex bound with at least one complex former comprising functional groups in the form of OH or NR.sub.3, (R=H or alkyl). Hard constituent powder and optionally soluble carbon source are added to the solution. The solvent is evaporated and the remaining powder is heat treated in an inert and/or reducing atmosphere. As a result, coated hard constituent powder is obtained, which after addition of a pressing agent and optionally with other coated hard constituent powders and/or carbon to obtain the desired composition, can be compacted and sintered according to standard practice.

Abstract: A method for producing a washer having a boss comprises the following steps in the sequence set forth: (a) sprinkling powder of a bearing alloy onto a backing metal made of an iron-based alloy to form a composite material; (b) sintering the composite material to obtain a bimetal material so as to accomplish a primary sintering; (c) fabricating the bimetal material into a shape of the washer having the boss; and (d) simultaneously accomplishing a secondary sintering and carburizing of the washer having the boss. By virtue of simultaneously conducting the secondary sintering and the carburizing for the washer, the number of steps in producing method (particularly, during a heat treatment) is reduced thereby improving the productivity of the washer having the boss while reducing thermal energy required for the heat treatment.

Abstract: There is disclosed a new process for binder phase enrichment. The process combines binder phase enrichment by dissolution of cubic phase with the requirements that cause formation of stratified layers, resulting in a unique structure. The new structure is characterized by, in comparison with the ones previously known, deeper stratified layers and less maximum binder phase enrichment. The possibility of combining dissolution of the cubic phase with formation of stratified layers offers new possibilities to optimize the properties of tungsten carbide based cemented carbides for cutting tools.The new process offers possibilities to combine the two types of gradients. The dissolution of cubic phase moves the zone with maximum mount of stratified binder phase from the surface to a zone close to and below the dissolution front.

Abstract: A method for producing high density and/or high surface density ferrous powder metal parts has the steps of: compacting a iron-containing powder substantially free of graphite at room temperature and at about 40-50 tsi; sintering the green compact in an inert, non-oxidizing environment at a temperature of about 2050.degree.-2300.degree. F.; repressing the sintered compact at room temperature at about 60 tsi; carburizing the repressed compact at high temperature to form a layer of relatively high carbon concentration to a depth of at least about 0.010 inches; and immediately quenching the hot carburized compact followed by a tempering treatment.

Abstract: A method of producing bearing surfaces from powder metal blanks comprising: blending carbon and ferro alloys and lubricant with compressible elemental iron powder, pressing the blending mixture to form the powder metal blank, high temperature sintering the blank in a reducing atmosphere, compressing the powder metal blanks so as to produce a densified layer having a bearing surface, and then heat treating the densified layer.

Abstract: A shaped material comprising powders of alloys containing easily oxidizable elements is fired in a hydrogen-based atmosphere containing at least one hydrocarbon gas in a total amount of 0.01-5.0 volume %. Therefore, the amount of oxides formed on the surfaces of material powder particles is reduced, and the sinterability of powder particle surfaces is improved owing to the sticking of atomic carbon thereto and thereby the mutual diffusion of powder particles becomes easy. As a result, there can be obtained a sintered alloy of desired density, superior in oxidation resistance, etc.

Abstract: The present invention relates to a novel method of manufacturing a composite body, such as a ZrB.sub.2 -ZrC-Zr composite body, by utilizing a carburization technique. Moreover, the invention relates to novel products made according to the process. The novel process modifies the residual parent metal which remains in a composite body, by exposing said residual metal to a carburizing environment. Thus, by modifying the composition of residual parent metal, the properties of the resultant composite body can also be modified. Parent metals such as zirconium, titanium, and hafnium are well suited to be treated by the carburizing process according to the present invention.

Abstract: A coated cemented carbide alloy having jointly a high toughness and high wear resistance is produced by specifying the cooling rate during sintering in efficient manner, which alloy comprises a cemented carbide substrate consisting of a hard phase of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of Group IVa, Va and VIa metals of Periodic Table and a binder phase consisting of at least one member selected from the iron group metals, and a monolayer or multilayer, provided thereon, consisting of at least one member selected from the group consisting of carbides, nitrides, oxides and borides of Group IVa, Va and VIa metals of Periodic Table, solid solutions thereof and aluminum oxide, in which the hardness of the cemented carbide substrate in the range of 2 to 5 .mu.m from the interface between the coating layer and substrate is 800 to 1300 kg/mm.sup.

Abstract: A three step process in which a metal alloy selected from a tungsten based alloy and molybdenum based alloys is provided to prevent the decarbonization of the alloys. The process involves a three step sintering process wherein the atmosphere during the initial heating step is a mixture of carbon monoxide and hydrogen, thereafter at a intermediate temperature range the atmosphere is hydrogen and a final heating step at a elevated temperature is employed and the atmosphere is a mixture of inert gas and a source of carbon.

Abstract: The invention involves a method for making powder metal forging preforms of high strength ferrous-base alloys in which the times and temperatures for reducing oxides, sintering, and carburizing are substantially reduced as compared to conventional techniques. The method includes simultaneously sintering and carburizing the preforms in the hot zone of a sintering furnace at temperatures below 2000.degree. F. and for a period of time above austenitic temperature not exceeding about 35 minutes. After carburizing the preforms are rapidly cooled to freeze the case carbon gradient obtained in the hot zone.

Abstract: A rotary cutting tool for processing a metal workpiece includes an elongated solid body composed of cemented carbide containing cobalt. The body has cutting edge means at its forward end and an axis of rotation therethrough. The body has a surface of which cobalt content is greater than that of the remainder of the body. Part of the surface of the body is ground to remove the cobalt-rich surface therefrom.

Abstract: A method for producing a sintered ferrous alloy containing at least one alloying element whose standard free energy for oxide formation at 1,000.degree. C. is 11,000 cal/g mol O.sub.2 or less is described. The method comprises a sintering procedure comprising steps of elevating the temperature of a green compact comprising said at least one alloying element, sintering it in a sintering furnace and cooling it, wherein the pressure in the sintering furnace is maintained at between about 0.2 and 500 Torr by supplying a reducing gas during at least a part of the sintering procedure under reduced pressure.

Abstract: A copper-rich metal shape is produced by forming a coherent forerunner shape consisting essentially of cupreous powder, said powder containing a proportion of copper oxide sufficient for facilitating the obtaining of a high sinter density in sintered porous mass, and in a reducing atmosphere at temperature that will sinter copper present, converting said forerunner shape into a porous sintered mass virtually devoid of copper oxide. Said porous mass can be worked so virtually full density if desired.

Abstract: A powder metallurgical method is described for producing precision components of sintered steel having high strength and high ductility by compressing a powder to form a green compact and sintering the latter at a temperature from 950.degree. to 1250.degree. C. for 5 to 90 minutes in a reducing atmosphere of partially combusted hydrocarbons, sufficient carbon being present to impart a carbon content of 0.05 to 0.6% by weight in the sintered steel; said powder consisting essentially of iron powder containing 0.65 to 0.8% phosphorus, 0.1 to 0.5% graphite or carbon powder, and 0 to 1.5% of a solid lubricant.

Abstract: The present invention provides a method for controlling the carbon content of dewaxed carbide preforms in a carbon containing furnace. The method includes the steps of placing the preforms in a carbon containing furnace and then heating the furnace to a predetermined temperature range between 800 and 1100 degrees Centigrade. At that temperature, a mixture of methane and hydrogen is introduced into the furnace chamber such that the amount of methane is between 10 and 90 percent of the amount of methane present at equilibrium for the reaction C.sub.solid +2H.sub.2 .revreaction.CH.sub.4. The furnace chamber is maintained at its temperature for a first time period sufficient for the chemical reaction XC+2H2.revreaction.X+CH.sub.4 (where X is selected from the group of W, Ti, Ta, Hf and No) substantially reaches equilibrium but shorter than the a second time period in which the reaction C.sub.solid +2H2.revreaction.CH.sub.

Abstract: A process for high temperature sintering of ferrous powder metallurgy compacts having a substantially uniform carbon distribution which comprises:(a) heating the ferrous powder metallurgy compact in the heating zone of a sintering furnace to a temperature of about 2,300.degree. to 2,550.degree. F. (1,260.degree. to 1,399.degree. C.),(b) introducing to the heating zone an atmosphere comprising about 2 to less than 10 volume percent hydrogen, about 0.5 to 2.0 volume percent carbon monoxide, about 0.5 to 1.0 volume percent methane and the balance nitrogen, and(c) removing the sintered product from the furnace.

Abstract: Porous bodies are produced by sintering a body of nickel powder incorporating from 0.35 to 2.0% by weight of carbon under a reducing gas at a temperature above 750.degree. C. but below 1050.degree. C. At least part of the carbon may be mixed with the powder as finely divided graphite.