SU724080A3 - Method of making coins of sintered metallic powder - Google Patents

Abstract

Ti coins are produced by cold-pressing Ti powder, under sufficient pressure to form a coin blank, the density of which is 60-90% of its theoretical density. The blank is stamped with stamping tools, at sufficient pressure, pref. (9.45-15.75) x 103 atmos., to yield a Ti coin, the density of which is >=90% of its theoretical density. Density control minimises erosion of stamping tools. Ti powder is non-toxic, easily available, and cheaper than Ni. High productivity can be achieved cheaply by powder-metallurgy. Dimensional control is easily carried out. Ti alloys with specific properties can be produced. Particles of other materials can be added before pressing. Density and conductivity can be adjusted. Ti retains its appearance for a long time.

Description

This invention relates to metallurgy powders, in particular, to methods for producing coins from metallic titanium powder. A known method of manufacturing coiled articles such as medals from a mixture of metallic powders of copper and tin, as well as from iron powder, including pressing a mixture of powders, sintering, calibrating and applying a protective coating 1. The method is highly economical, but it does not provide the possibility of obtaining coins from titanium. The closest in technical essence and the achieved effect to the invention is a method of making coins from sintered metal powder, which includes squeezing and embossing the pressing of powder blanks. The method provides for the manufacture of coins in the form of bimetallic products 2. However, the use of a known method in the manufacture of titanium coins causes difficulties due to poor machinability of titanium, since high pressure in the process of minting is required to obtain high-density coins, which leads to a decrease in durability of the pressing tool. . The object of the invention is to reduce the pressure of the coinage while maintaining the high density of titanium coins and increasing the durability of the pressing tool. This is achieved by the fact that in the method of making coins from sintered metal powder, which includes pressing, sintering and embossing, the titanium powder is pressed to a density of 60-90%, sintered at a temperature of 1010-1204 s, and the embossing is carried out at a pressure of 9-15 t / cm Moreover, when pressing titanium into a powder, a solid insert of ferromagnetic or nonmagnetic material is introduced, for which one of the metals selected from the iron j group is used. nickel, copper, aluminum. In order to give coins of different colors, after minting, coins are heated in aaot or oxygen-containing atmosphere. Example. From titanium powder, blanks with a density of 60, 70, BO and 90% are pressed, they are hidden at 1010

Claims (4)

The formula for the invention of sintered including sintering and shch ’and th with I in the trading apparatus. To give the coins a certain color after minting, they are subjected to heating in a nitrogen or oxygen-containing atmosphere. To obtain a gold color, the coins are heated at 343 ° C in an oxygen-containing atmosphere .; By heating the coins in air at 593 ° C, a blue color with a golden tint is achieved. Heating in a nitrogen-containing atmosphere at 593 ° C gives the coins a blue color. The proposed method provides 1. The method of manufacturing coins from metal powder, pressing the latter, minting, is distinguished by the fact that, in order to reduce the pressure of minting while maintaining the high density of titanium coins and increase the wear resistance of the pressing tool, titanium powder. They are pressed to a density of 50-90%, special operations are carried out at a temperature. P- „is carried out when obtaining coins from titanium with a density of up to 98% at a minting pressure of 9-15 t / cm ² , which creates a complete filling of the stamp with good coin minting. At the same time, the use of low embossing pressures in combination with the regulated initial density of the billets and the regulated sintering conditions allows the creation of 1 01 0-1 20 4 ° C, and the embossing with a pressure of 9-15 t / cm ² . , 2. The method according to claim 1, in that when pressed into a titanium powder, a solid insert of ferromagnetic or non-magnetic material is introduced. 3 .. The method according to claim 2, characterized in that one of the metals selected from the group is used as the insert material; iron, nickel, copper, aluminum. 4. The method according to claim 1, characterized in that, in order to give the coins a different color, after minting, the coins are heated in a nitrogen or oxygen-containing atmosphere.