US2090836A - Particle inlaid surface - Google Patents

Description

ug. 24, 1937.I c. s. GLEZEN 2,090,836

PARTICLE INLAID SURFACE Filed July 24, 1935 3 L Mazo /SA/Vo/ ORNEY' Patented Aug. 24, 1937y 2,090,836

UNITED STATES PATENT FFICE PARTICLE INLAID SURFACE Carlisle s. Glezen, Baldwin, N. Y., assigner?v to The Safe Tread Company, Inc., New Yorky, N. Y., a. corporation o! Delaware Application* July 24, 1935, Serial No. 32,840

Claims. (Cl. 22-202) This invention relates to methods for the faces, it is not limited thereto, but is understood manufacture of cast metal articles wherein some to be applicable to analogous arts and the deof the surfaces of the finished article are inlaid scription given is understood to be exemplary with particles, etc., such as abrasive particles, thereof.

5 etc., aixed by flowing the metal around themA This invention has for its object the provision 5 during the operation of molding. A most charof@ method of inlaying particles in a cast metal acteristic or common form .of particle inlaid cast surface whereby control of the final distribution metal surface is the common abrasive inlaid cast of the particles over the surface is more easily metal safety floor and stair read. This invenobtained. It has .for another important! obtion has to do specically th methods for ject the provision of amethod of inlaying wherel0 the manufacture of such objects which permit of by a firmer bonding of the inlaid particles to the economically securing control over .the distribumetal may be had. It has for an object the tion of the inlay-particles in the metal surface provision of a process whereby the surface of and of securing a iirm bond between the parsuch products may be freed to a great degree l5 tides and the metal, 4 i from the presence of slag, oxide films and the 15 In the present art of forming particle inlaid like. It has other objects and advantages which cast metal surfaces, many methods are followed. will be in Dart ObVOuS and Part 0f Which Will 'De For instance: A mold may be prepared and the peinted Out hereafter. inlay-particles may be sprinkled therein, the It has been observed that in the casting of thin pattern returned to the mold and tamped to metal sections, as the metal flows over the mold force the inlay-particles into the mold surface',`... Surface. lt ClOeS not behave eS Would a liquid after which the pattern is removed, the mold Which Wetted the mold but behaves somewhat closed and the metal poured. 'Another method aS dOeS mercury flowing over a 4surface which is the sprinkling of a powdered refractory mateit does not Wet, in that a Slight Skin or film of rial, such as fire clay on the face of the mold, impurities. OXideS and/0r colder metal forms on 25 followed by sprinkling the inlay-particles on the the Surface 0f the metal, and aS the metal flOWS, nre clay, after which the mold is closed and the thiS Skin iS rolled under the advancing Wave 0f metal poured. Or the inlay-particles may be metal and depOSted between the more fluid coated with an adhesive composition, such as metal and the mold surface somewhat as a carsodium silicate, and sprinkled into the mold, Det- Due t0 this, it may be Seen that the ad- 30 and after the adhesive is dried by any of several Vancing metal iS not Capable 0f flowing freely means, the mold may be closed and the metal inte ihterStiCeS aS Would a llmpid liquid, but poured. Another process involves the coating acts sOmewhat more in the fashion of a blunt of the mold face with adhesive and sprinkling and soft scraper and will to a great extent tend the inlay-particles thereon. Attempts have been t0 Push beOre it Small Particles in its path, 35 made to use inlay-particles coated with very inerather than t0 immediately Surround them. It ly divided metallic particles to secure a bond iS my belief that this behaVOir 0f flowing metal to the metal, and various other methods have in a mold is responsible for many 0f the difbeen used. I have observed that in all of these eultleS encountered in Obtaining unifOrm 0I' methods there is some tendency for the inlaycontrolled distribution of inlaid particles, since 40 particles to be displaced when metal is poured a 110W of this Sort Would tend sOmeWhat to break into the mold, and in many of them it is quite the bond (however it is arrived at) by which marked. `In many of these processes for one the inlaid particles are held to the surface of the reason or another, the inlay-particles are quite meld and then would tend to displace them.

lmperfeetly imbedded in and/or bonded to the 0r if the inlaid particles are of lower specific 45 metal. A gravity, then, being loosened, they might later This art, as well as the present invention, is rise into the molten metal and so escape from also applicable not only to processes for inlay the surface where their presence is desired. It ing the surfaces of cast material with abrasives, iS my belief that this formation 0f a Skin 0r lm but for the in1aying of a. cast metal surface with of slag impurities 0r oxides 0r colder metal sep- 5o particles of any nature such as with other metals arately or in combination, or whatever it may be, or corrosion resistant particles of any nature, also is a major underlying cause that Prevents or other related arts, and while the discussion the securing of a good bond between the inlaid i, of the present disclosure is directed largely to particles and the metal. If the skin be slag or the production of abrasive inlaid wearing suroxide, it will persist between the body of the 55 metal and the inlaid particles, and prevent a good bond. If it merely be colder metal, it will be more viscous and so will not flow freely into the interstices by the inlaid particles and Iso 5 will not completely surround and imbed them in metal. It the skin bea combination of impurities and colder metal, the result will be the same, but more pronounced.

I have found that by so arranging my mold as to rupture this skin at frequent and repeated intervals and so maintain conditions wherein unfilmed higher temperature limpid metal repeatedly and rapidly may be liberated and brought in contact with the inlay-particle carrying mold surface, I

may secure a more even distribution of the inlaid material and a more perfect bonding of the inlaid material with the metal. My method consists of using a mold in which obstructions of a character and distribution designed to secure this repeated nlm rupture are placed so that the advancing wave of metal will contact them, and of distributing the inlay-particles in the mold with such respect to these obstructions that the benets of the film rupture may be best secured. For

the purposes of the present description, I will A refer to these obstructions as dams. It is my belief that as the advancing flow of metal encounters'and rises over each of these dams, it is piled up to some slight extent and this piling forces a breaking of the skin formed around the metal and permits hotter, less viscous, and cleaner metal to flow from the interior of the advancing body of metal to surround the inlay-particles J'ust in advance of the point of rupture of the fllm.

It is my belief that a greater portion of the advantages and objects of this invention are attained by this action, although I also believe that the presence of the dams tends to break up the sweep or ilow of metal and cut down the velocity 40 of that portion of it adjacent the inlay-particle carrying mold surface, and that this also contributes a portion of the results noted.

What I have found is that in the production of a particle inlaid surface, if the mold be formed so that it presents dams or obstructions to the ilow of metal, if these obstructions be reasonably continuous, if they be placed generally transverse to the direction of ilow of metal when casting, if the proportions between the height of obstruction and spacing between obstructions be proper,

and if inlay-particles be placed on the mold surface between such obstructions, then the various objects and advantages mentioned herein may be obtained.

In order to illustrate this invention, I now make reference to a drawing which is attached to and forms a part of this specification. The single ilgure of this drawing represents a diagrammatic section of a mold with metal flowing thereinto, in

which I represents the mold, 2 represents the grains of inlaid material on the surface thereof, and 3 represents the dams. 4 is intended to represent the metal iiowing into the mold and 5 is intended to represent the hn or skin of oxide, or

slag-like impurities or of colder metal of which I have spoken above. It will be noted that the direction of flow is assumed to be from left to right and that the dams are placed in a direction transverse to that of the flow of metal. It will be observed that in mounting the dam 3 next the lefthand end, that the metal has piled up behind the dam to an extent which has enabled the hotter metal from the interior to break through the skin and to ilow over the dam into the succeeding pocket and surround the inlaid material therein with a metal which is generally free from this film or skin and which is considerably hotter (possibly 200500 F.) than the metal which would normally have been brought in contact with this inlaid material had the film remained unbroken. It will also be observed that adjacent the next dam 3 the im is again forming over the surface of the advancing metal and it must again be broken in order that the hot metal from the interior of the flow may be released' to come in contact with the inlaid material to the right of this second dam 3. It will also be observed that these dams are so positioned as to break up and lessen the velocity of sheet flow of the metal over the surface of the mold.

The dimensions and spacing of the dams or of the dam forming grooves in the pattern are of importance. I have found that the minimum dimensions of groove to obtain this beneficial result are determined by the following considerations. The depth of groove should preferably be not less than ik", as the beneficial results disappear quite rapidly below this depth. A greater depth of groove will not give increases in protection corresponding to the increases in depth of groove; and too great a depth of groove, say of the nature of 1/2 gives rise to a cascade action of metal on the down stream side, which may displace the inlaid material. As for width, the width of the groove in the pattern or the width of the dam in the mold need only be enough to give the dam suflicient strength to withstand the impact of the flowing metal. I have found for example,

that with a groove 1A," deep, a preferable width.

is about 1A?. 'I'he proper spacing of the grooves or dams is of special importance. This depends to some extent upon the depth of metal above the dam, that is upon the thickness of the nnal casting, since in thin sections, the amount of highly heated metal which may flow from the interior of the advancing body after rupture of the film is much less than with thicker sections, and the exact spacing of the grooves depends therefore upon the thickness of the casting to be made. I have found for instance, that on castings only thick, that the spacing between grooves should not be in excess of approximately V4", while on castings 11/2 thick, or in excess of that thickness, a spacing of the grooves 11/2 apart gives rise to good results. For castings of thicknesses between these limits, proportional changes should be made in the spacing of ,the grooves.

With respect to the disposition and general configuration of the dams, the following may be noted. The dams may be continuous or discontinuous, but if discontinuous should not be so short in length that the film is merely punctured by the individual short dam instead of broken for some little space. The dams should be so placed on the mold surface that they are in gendirection of iiow of the entering metal. They may well be disposed in intersecting or interlaced groups to form a pattern in the surface of the :final product. Heretofore, I have spoken of the dams as being composed of mold material, and resulting in a groove in the final molded surface. I am not restricted thereto, but find myself able to use andcontemplatethe use of dams in the mold, which dams are themselves composed of metal or other material, alike or different from the casting body metal and from the inlay-particle material and which, when the operation of casting is finished, will themselves appear in the form of an inlay in the cast surface.

It is to be noted that I may place my inlayparticles in any predetermined location, and amx them there by any of the methods herein discussed. For example; if I am making a stair 5 tread with abrasive inlay, I may place large quantities of abrasive near the front edge, for wear resistance as Well as friction, and only place enough in the rest of the tread for friction purposes, and may be assured that the distribution 10 in the nal product Will be as planned.

I claim:

1. The method of manufacturing articles having particle-inlaid cast metallic surfaces which comprises the steps of providing a mold having 15 a surface on which the inlay-particles are distributed, admitting molten metal to such mold to ow over said mold surface, and while said metal is flowing, repeatedly interrupting the flow and rupturing the film formed over the advancing 20 body of metal to permit portions from the in terior thereof to ow forth and surround the inlay-particles adjacent the advancing metal.

2. The method of manufacturing particle-lnlaid cast metallic surfaces comprising admitting molten metal to a mold to ow over and be formed by a surface upon which inlay particles are distributed, said mold surface being additionally provided with obstructions so distributed as to prevent ow along the surface in any direction for any substantial distance and of such. size as to cause the metal which overows the obstruction to come preponderantly from within the obstructed body of flowing metal.

3. The method of claim 2 in which the obstructions are in the form of molded dams from 1,/8" to 1/2" in height and spaced from 1A" to 11/2" apart.

d. The method of claim 2 in which the obstructions are molded dams disposed in interlacing patterns upon the surface of the mold.

5. The method of claim 2 in which the ob.

structions are themselves an inlay material and upon cooling of the casting remain in the surface thereof as an inlay, with particles of additional inlay distributed in other portions of the surface.

CARLISLE S. GLEZEN.

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