SU582909A1

SU582909A1 - Method of making sintered articles

Info

Publication number: SU582909A1
Application number: SU7502177419A
Authority: SU
Inventors: Валентин Петрович Перевезенцев; Валерий Александрович Пискунов; Анатолий Николаевич Вощанкин; Анатолий Петрович Мартынов
Original assignee: Предприятие П/Я М-5409
Priority date: 1975-09-30
Filing date: 1975-09-30
Publication date: 1977-12-05

Description

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Изобретение относитс к порошковой металлургии, в частности к способам изготовлени спеченных изделий посредством уплотнени и спекани пр мым пропусканием электрического тока. The invention relates to powder metallurgy, in particular, to methods for manufacturing sintered products by compacting and sintering by passing an electric current.

Известен способ изготовлени спеченных изделий, заключающийс в одновременном уплотнении заготовки в токонепровод щей оболочке с одновременным пропусканием через заготовку элек трического ТО : .A known method of manufacturing sintered products consists in the simultaneous compaction of the workpiece in a non-conductive sheath while simultaneously passing an electrical MOT through the workpiece :.

Недостатком известного способа вл етс неравномер- ть нагрева заготовки по сеченмю, ч: о приводит, при изготовлении изделий из углеродистого наполнител и св зующего, к миграции жидкого св зующего к периферии заготовки и неравномерности состава и свойств по объему издели .The disadvantage of this method is the uneven heating of the billet over the section, h: o, in the manufacture of products from carbon filler and binder, to the migration of liquid binder to the periphery of the billet and uneven composition and properties by volume of the product.

Наиболее блкзкмл по технической сущности и достигаемому результату вл етс способ изготовлени спеченных изделий, заключающийс в уплотнеНИИ заготовки в токонепровод щей пресс-форме и одновременном нагреве заготовки пропусканием электрического тока через граничный слой, образующий боковую поверхность пресс-формы 2.Most technical essence and achieved result is the method of manufacturing sintered products, which consists in compacting the workpiece in a non-conducting mold and simultaneously heating the workpiece by passing an electric current through the boundary layer forming the lateral surface of the mold 2.

Недостатком известного способа в|л етс то, что нагрев заготовки осуществл етс с поверхности, что приводит к градиенту температуры в ее объеме и к низким свойствам изделий.The disadvantage of this method is that the heating of the workpiece is carried out from the surface, which leads to a temperature gradient in its volume and to low properties of the products.

При изготовлении спеченных изделий из углеродистого наполнител и св зуощего плотнр ть изделий составл ет 1,5 г/см (пористость 25%), удельное росопротивлеИие 65ом мм/м, предел прочности при сжатии 250 кгс/см .In the manufacture of sintered products from carbonaceous filler and binder, the density of the products is 1.5 g / cm (porosity 25%), the specific resistance of 65 ohm / m, the compressive strength of 250 kgf / cm.

лвлью изобретени вл етс повЫшеHVа свойств изделий из углеродистого нлполйител и св зующего.One of the inventions is the higher HV properties of carbonaceous binder products and a binder.

Дл этого предложен способ изготовлени спеченных изделий, который отличаетс от известного тем, что уплотнение заготовки осуществл ют одновременно с уплотнением граничного сло , выполненного из углеродистого наполнител .To this end, a method has been proposed for the manufacture of sintered products, which differs from the known one in that the compaction of the preform is carried out simultaneously with the compaction of a boundary layer made of carbonaceous filler.

Оптимальной вл етс толщина граничного сло , составл юща 0,05-0,2 от максимального размера сечени прессформы .The optimum is the thickness of the boundary layer, which is 0.05-0.2 of the maximum size of the cross section of the mold.

Claims

In the proposed method, the billet is heated from the outer layer of conductive carbonaceous filler, while uniform heating of the billet is achieved in terms of volume and uniformity of properties over the cross section of the products. Products have high operational properties. Example. In a non-conducting mold, a layer of conductive filler — petroleum pyrolysis coke — was placed at the bottom. A thin metal holder equidistantly spaced from its walls was placed in the mold. A portion of the material — petroleum coke with a binder from coal-tar pitch — fell into the cage. The coke was filled with petroleum coke into the gap between the mold and the holder: Then the holder was removed, the matrix was closed with conductive punches, a pressure of 300 kgf / cm was applied and current was applied to the punches. The pressing temperature was 40–50 minutes. The products had the following properties; loricity 17%, density 1.7 electrical resistivity 40 ohm%% compressive strength 350 kgf / / cm. The invention method of making sintered products, including sealing the workpiece and simultaneously heating it by passing electric current through the boundary layer, characterized in that, in order to improve the properties of the carbonaceous products and the binder, the workpiece is compacted simultaneously with the sealing of the boundary layer from carbonaceous filler. Sources of information taken by time in the examination: 1. US patent. 3001237, cl. 18-54,7. 1961.

2.Seysan kenkyu, kettkyu, MoMihFy J.JMbt- Mduutr.Se UMiVjToKyo. 968.20, No. 9, 460-470.