US2328788A - Method of bonding ferrous and nonferrous metals - Google Patents

Description

2 Sheets-Sheet l HORA H. E. DEPUTY Filed Nov. 28, 1941 Sept. 7, 1943.

METHOD OF BONDING FERROUS AND NON-FERROUS METALS Sept. 7, 1943.

' H. E. DEPUTY METHOD OF BONDING FERROUS AND NON-FERROUS METALS 2 Sheets-Sheet 2 Filed Nov. 28, 1941 FIG 5- l2 INV EN TOR.

ATTORN HORACE E.DEPUTY' LLLL Patented Sept. 7, 1943 METHOD OF 2,328,788 BONDING FERROUS AND NONFERROUS METALS Horace E. Deputy, Brooklyn, Mich.

Application November 28, 1941, Serial No. 420,781 I I 2 Claims.

This invention relates to methods of bonding ferrous and non-ferrous metals, constituting a further development of-the invention disclosed in my Patent No. 2,123,181, granted July 12, 1938.

Animportant object of the present invention is to provide an improved method whereby such metals may be intimately and permanently bonded one to the other, in a simple, quick and positive manner which lends itself to rapid production methods, and which enables a large number of such bonding operations to be performed in a short space of time, even though relatively large masses of metal are to be united.

While the invention is illustrated as ap lied to seeming together a steel cylinder and an encircling aluminum sleeve or muff. adapted to be used in the construction of air-cooled engine cylinders, many other applications will be readily understood to exist.

Other objects and advantages will readily occur to those skilled in the art upon references to the following description and accompanying drawings.

In the drawings:

Fig. 1 is a plan view of a mold assembly adapted to be used in carrying out my improved process.

Fig. 2 is a diametrical cross section taken substantially on the line 2-2 of Fig. 1, and looking in the direction of the arrows.

Fig. 3 is a detail section taken substantially on the line 3-3 of Fig. 1.

Fig. 4 is a central vertical section through the mold taken substantially on the line 44 of Fig. 1, and with adjacent supports and mechanism shown in elevation with portions broken away.

Fig. 5 is a diagrammatic plan view of the mold, its supporting stand, and a preferred relative positioning of the cooperating reducing oven and hydraulic press utilized in my improved method.

Fig. 6 is a detail sectional view, taken substantially on the line B6 of Fig. 1, showing the mounting of one of the mold heating'elements, and

Fig. '7 is a front elevation of a reducing oven used in my improved method.

Referring now to the drawings: The method employed insofar as the formation of the bond itself is concerned, is similar to that disclosed in my Letters Patent No. 2,123,181, above referred to, although additional steps are employed and the rapidity of production of the bonded parts is thereby increased.

In the mold construction shown, a central generally cylindrical cavity I0 .is provided, the ex-' ternal'walls of which constitute the outer mold walls for the formation of the muif" or aluminum sleeve. This is to be cast upon the exterior of a steel cylinder liner 0;,- the like, as l2. The liner is adapted to stand in concentric position projecting upwardly from the bottom .of the mold, and to form the inner wall of the mold cavity into which the aluminum is poured during casting. The liner i2 is positioned by an annular bottom clossure member i3 which defines the bottom of the space ill, but is centrally open to permit escape of the cooling fluid, which is supplied, as will presently be described, through pipe 30. v

A pouring sprue l4 leads to the bottom of space Ill, and terminates at a gate. IS in an adjacent part of the mold assembly. These parts will be seen to be located upon the parting line of the mold sections, and the general arrangement of these mold parts will be seen to be in accordance with conventional foundry practice. The mold sections 8 and 9 are adapted to be secured together by bolts as ii, the threads and cooperating nuts l8 of which are preferably of the quick opening variety, as shown in Figs. 1 and 3. Electrical or other suitable heating elements 20 may aslo be incorporated in the mold assembly if desired, to facilitate preheating. As herein illustrated, heating elements 20 of the "globar type are shown in Figs. 1, 2 and 6. These heating elements 20 extend laterally through the mold sections, and carry terminal clamps 2| at their ends, which connect with suitable flexible electrical conductors, as 22. As shown, a plurality of globars are mounted in each mold section.

The top wall of the cavity III is defined by another annular closure 25, which is adapted to be lifted by and float upon the poured metal, whereby it may serve as a compression member, through the agency of which pressure may be directly applied to the poured metal to compact the same and collapse any voids which may exist therein.

In carrying out my improved process, the ferrous metal, which in this instance is the steel sleeve or cylinder liner I2, is first preheated to a temperature of 500 to 850 F., in a reducing oven, as 40, after having been previously dipped in a galvanizing bath of molten zinc, preferably of the variety sold commercially, as Western Spelter. As pointed out in my Letters Patent above referred to, the impurities present in this particular material seem greatly to assist in securing uniform bonding (such impurities consisting principally of lead, iron and cadmium).

The galvanized sleeve is guarded against oxidation. It may either be kept hot after galvanizing, and placed in the mold while heated to a temperature of from 500 to 850 F., or may be allowed to cool and then be reheated to bring it to the proper temperature at the time of pouring, but in either event the heating of the galvanized sleeve is preferably effected in a reducing oven, as 40.

The mold is also preheated, to a temperature of from 750 to 850 F. at the time of pouring, and the aluminum is poured at a temperature of approximately 1300 F. The aluminum may either be in the pure state or alloyed with other metals, as desired. Preferably, the pouring is done as quickly as possible after the sleeve is removed from the reducing oven and placed in the mold, so that no opportunity for substantial oxidation of the sleeve is afforded.

After the poured aluminum has been allowed to stand from five to ten minutes, to permit it to solidify in the sprue, pressure is applied to the compression ring 25, to compact the metal in the cavity III while it is still relatively soft.

About one minute after pouring commences,

also, cooling fluid, such as water, brine, or oil,. .1 is directed against the interior of the sleeve 12,!

through the pipe 30, which projects into the interior of the sleeve and is provided with a plurality of relatively fine orifices 33 arranged to project jets against the interior of the sleeve..

a heated sleeve l2 can be removed through the door 42 and immediately placed in the mold to keep oxidation at a minimum. At the other side of the mold, a hydraulic press 50 may be mounted, as upon a swinging bracket 5| secured on a wall 52. The plunger 53 of the hydraulic press carrics a member 54 adapted to contact the annular closure member 25 when swung into position, as shown in dotted lines in Figure 5. The closure member 25 is preferably formed with a shoulder 26 to limit its travel into the mold aperture l0 and so limit the compression exerted on the soft metal being compacted.

The application of cooling fluid to the internal surface of the sleeve while the molten aluminum is in contact with the external surface thereof can be arranged to prevent a drawing of the temper of the steel sleeve or softening it beyond the desired Brinnell gauge. This is important when the sleeve is to be used as a liner for an airplane or similar engine cylinders, and the aluminum muff is the air cooling sleeve thereon. By preventing the ferrous sleeve from reaching a temperature sufficient to unduly soften it, is only necessary to maintain the cooling fluid at a sufllciently low temperature, and initiate the flow of the cooling fluid when the sleeve is being heated by the molten aluminum close to the softening temperatures.

I am aware that the invention may be embodied in other specific forms without departing from the spirit 'or essential attributes thereof,

and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive; reference being had to the at least partly alminum, which consists in coating at least the outer periphery of the ferrous sleeve with a coating consisting principally of zinc, preheating the coated surface of the sleeve while limiting access of oxygen to the coated surface, pouring the non-ferrous metal in molten condition into engagement with the coated surface of the sleeve, allowing a time interval of approximately one minute after pouring commences, then projecting a spray of cooling liquid into the interior of the sleeve, allowing a further time interval of at least four minutes, and then applying mechanical pressure to the non-ferrous metal to compact the same and urge. it into engagement with the coated surfaceof the sleeve.

2. The process set forth in claim 1 wherein the coated ferrous sleeve is preheated to a temperature of from 500 to 850 degrees F., and then placed in a mold preheated to a temperature of from 750 to 850 degrees F. to receive the molten non-ferrous metal.

HORACE E. DEPUTY.

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