SU23620A1 - The method of manufacturing products from hard alloys - Google Patents

Description

The invention relates to a method for manufacturing hard alloys. A common method for making hard alloys is to mix tungsten or molybdenum carbite with additional, more fusible metals, then the mass is pressed and sintered. In addition, for each product, a specially made shape is required and the range of products is very limited due to this method of molding, since pressing only prism or cylindrical forms is possible. After pressing, the product is subjected to pre-sintering at a low temperature before processing, giving them greater strength, but the products remain extremely fragile. The proposed method is aimed at eliminating the difficulties listed above and making it possible to obtain products of almost any form.

Tungsten carbide or molybdenum carbide powder, or chemically produced alloys, such as cobalt, iron, nickel, cobalt tungsten, etc., ground and mixed with glue-like or resinous substances, such as a solution of nitrocellulose, casein, bakelite, dry bakelite , turn into a more or less plastic mass. The plasticity of the mass depends on how it is shaped and shaped into the future product. If the required shape can be commercially obtained by pressing, it is better to use, for example, dry bakelite. The method of pressing is similar to the method of pressing plastic bakelite products. The mixture of carbide with additional metal is mixed with the required amount of bakelite lacquer, dried, ground and pressed in a hot mold before the bakelite is polymerized. The amount of bakelite and the degree of plasticity of the mass depends on the complexity of the mold. The limit is set by the carbon remaining from charring bakelite, which makes sintering difficult. With large quantities of carbon remaining, it is better to use carbits with a low carbon content. In this way, thanks to the plasticity and strength of the mass, from the mold, products of a much more complex shape can be obtained than by pressing from pure powder. In addition, the products from the mold are taken out very durable and can be processed and corrected without prior sintering, i.e. sintering can be done at one time. Sintering is carried out in the usual manner. If even greater plasticity of the mass is required, it is better to use thick glue-like solutions, for example, a solution of nitrocellulose. The nitrocellulose solution is thoroughly mixed with the powders and the resulting pasty mass is attached to the desired shape by any method. For example, various plates can be obtained by rolling, wires and rods of different diameters by mass punching through the hole, more complex shapes by casting under pressure, molding, etc. After drying, the products have great strength and can be easily finished. In view of its great strength, the products are sintered in one step. Molded products are different in porous bean mold material and dried in a mold. Cones, and sometimes shapes are made of a not very dense and easily charring or fire-resistant material and, if necessary, are sintered together with the product and only then removed or dissolved chemically.

The proposed method makes it possible to prepare from hard alloys thin sheets, hollow products, threads, products with curvilinear channels, the manufacture of which by previously known methods is difficult or even impossible.

The subject matter of the invention.

1. A method of manufacturing products of hard alloys, characterized in that a mixture of tungsten or molybdenum carbite powders with powders of more low-melting metals or alloys, such as cobalt, cobalt tungsten, etc., is mixed with resinous BeiMecTBaMHj, such as bakelite, of the resulting mass of the forglucp product by pressing into a hot mold or molded into a hot mass by other methods, after solidification, it is processed and sintered in one step.

2. The modification of the method indicated in paragraph 1, characterized in that the powders of carbide and additional metal are mixed with glue-like solutions, for example, nitrocellulose solution, the resulting plastic mass is obtained by casting, forcing, rolling, stamping, etc., and dried is processed and sinter in one step.