US986519A - Method of rendering porous metals dense. - Google Patents

Description

UNITED STATES PATENT OFFICE.

CHARLES E. SWETT, OF PROVIDENCE, RHODE ISLAND.

METHOD OF RENDERING POROUS METALS DENSE.

No Drawing.

To all whom it may concern: a

Be it known that I, CHARLES E. SWETT, a citizen of the United States, and resident of Providence, in the county of Providence and State of Rhode Island, have invented new and useful Improvements in Methods of Rendering Porous Metals Dense, of which the following is a specification.

This invention relates to a new art or method of treating a body or mass of porous, spongy or discrete metal to render the same more dense, and consists in applying to such mass a compound of the metal in a fluid state, in such manner that said compound of the metal will enter the porosities of the metal mass being treated, after which said metallic compound is reduced to the metal state in place in the porosities. This filling of the porosities with the metallic compound, and reduction, may be repeated as many times as necessary 0; desirable according to the degree of density required, and finally results in a solid, dense and homogeneous mass of metal which was origi nally porous or spongy.

It happens in the course of the manufacture of articles of silver or other metals, especially when certain processes are used, that the metal body, or some part thereof, is porous, and therefore not acceptable as a marketable commodity. For example, suppose an article, or an ornamentation in relief upon an article, be formed in the desired shape out of a plastic or fluid mass consisting wholly or chiefly of a reducible compound of a metal, such as the bromid, chlorid, iodid, fluorid or nitrate of silver, or of copper, or any of the reducible salts of a metal, and the mass or bodyso formed be then reduced tometal by any appropriate method of reduction, it will be found that the mass in its reduced state will be more or less porous or spongy.

To render such mass or body of porous metal more dense and solid is the chief object of the present invention. This is accomplished by applying to the mass or body of porous metal a compound of like metal in a fluid state, and thereafter reducing the fluid metallic compound to metal in place within the porosities. The porosities of the metal mass will absorb or imbibe the metallic compound, which has been rendered fluid by solution in an appropriate solvent or by heat. The reduction of the compound of the metal within the porosities may be Specification of Letters Patent.

Application filed May 12, 1908.

Patented Mar. 14, 1911.

Serial No. 432,515.

effected by any means appropriate to the particular material being used. After one such treatment of filling the porosities and reducing as aforesaid, the object will probably still be somewhat porous, and I there- 'silver chlorid, by washing or immersing the porous silver body in said fluid compound of silver. The fluid compound is absorbed by and soaks into the porosities, assisted by capillary attraction. I then reduce the compound to metal in place in the pores, by any well known and appropriate method of reduction. If silver nitrate in solution has been used, the reduction may be accomplished by heat. If melted silver chlorid has been used the reduction may be accomplished by electrolytic reduction, or by chemical reduction, in any manner well known to those skilled in the art. Should greater density be required than results from one application and reduction of the fluid compound, the treatment may be repeated until the pores are for all practical purposes filled.

While the foregoing exemplification of the invention is sufliciently characteristic admirably to illustrate the nature and principle of the invention, it will be understood that the invention is by no means limited to the manufacture or ornamentation of silverware, nor to any specific use, but is applicable to the treatment of porous metals generally, to render the same more dense, and such general application is contemplated by the claims.

I claim:

1. The method of treating a mass of porous or spongy metal to render the same more dense, which consists in filling the pores of said mass with a reducible comrous orspongy metal to render the same the same in the pores, until 'the mass so more dense, which I consists in filling the treated attains the desired density. 10 pores of said mass with a reducible c0m- Signed by me at Providence this 6th day pound of the metal in a fluid state,:an 'l of May, 1908. I

v thereafter reducing said compound to metal CHARLES E. SWETT.

' insuid pores, and thereafter repeating the Vitn'esses:

filling of the residual pores with a reduei- EM E'r'r GINLEY,

I ble compound of the metal, and reducing WASHINGTON R. PRESCOTT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). C.