US1096688A - Wear-resisting body and method of making the same. - Google Patents

Description

G. DANTSIZEN.

WEAR RESISTING BODY AND METHOD OF MAKING THE SAME.

APPLICATION FILED FEB. s, 1912.

1,096,688. Pat nted May12,191 l Fig.3.

WITNESSES JN YENTUH HI S ATTUHZYEY.

sequent to filing;

UNITED STATES PATENT OFFICE.

CHRISTIAN DAN'TSIZEN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ,ELEOTRIC COMPANY, A CORPORATION OF NEW YORK.

WEAR-RESISTING BODY AND METHOD OF MAKING THE SAME.

Specification of Letters Patent.

Patented May 12, 1914.

Application filed February 6, 1912. Serial No. 675,829.

To all w/mmc't may 0022 m:

Be it known that I, CHRISTIAN DANTSIZEN, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Wear-Resisting Bodies and Methods of Making the Same, of which the following is a specification.

My present invention comprises a material consisting of refractory earthy oxids such as the oxids of aluminum, beryllium, and titanium, in a very hard dense condition' free from crystalline structure and therefore especially valuable as a Wear-resisting body such as a die, I have discovered that these oxids, particularly alumina, Al. ,O can be sintered to a very dense state without actual fusion and consequent crystallization. The material is mechanically strong and far more durable than steel for the purposes mentioned. It is as hard as sapphire and possesses some of the desirable wearing quahties of diamond.

In the accompanyin drawings Figure 1 shows a preliminary form into which the material is shaped when it is intended to utilize it for a die; Fig. 2 shows the material after havin been trimmed in a lathe sub- Fig. 3 shows the finished die with its mount, and Fig. 4 shows the die and mount assembled in final form.

I will describe in its various stages the manufacture of a die from the loose oxid powder to the mounted die, referring in this description particularly to aluminum-oxid. I wish it understood that this description is also illustrative of other forms of tools, rolls, bearings, drills and the like.

Very finely divided aluminum oxid is mixed with about 10% of suitable binder such as gum tragacanth. When it is de sired to make a die for wire drawing the mixture is compressed into the form of a fiat cylinder which may be for example, one' fourth inch high and three-fourth inch in diameter. C linders or die blanks such as these are ba ed in an ordinary kiln at a temperature of about 1300 to 1400 C. After baking the substance has the consistency of chalk and therefore may be easily machined. The depression in the top of the die blank shown in Fig. 1 is increased along its axis so as to extend through the cylinder as shown in Fig. 2. When thus bored the cylindersare fired to 1800 to 2000 C.

or metal working tool:

in an inert environment.

A furnace suitable I for carrying out the firing operations is for alumina but it is a higher temperature than has been heretofore used to bake or fire alumina. I find it sinters the alumina into a very dense, amorphous or structureless condition in which it is very strong, fine grained and is hard as sapphire. This form of alumina is not to be confused with the commercial article known as alundum. The latter substance is an impure form of alumina which has been electrically melted and has a crystalline structure. When alundum is heated and plunged into water it cracks into pieces. Hig produced according to the above process may be heated to 1000 C. or even higher, and then may be plunged into water without dama e. In order to identify it from the slight y baked alumina heretofore'produced I may say it has a specific gravity of 3.8 to 3.9. It 1s capable of taking a high polish with diamond dust. It is opaque.

After having been fired as above described the dies are given their proper shape with. diamond dust and are then mounted in a casing illustrated in Fig. 3, the die 2 placed in a recess prepared for it in the steel or 11y sintered alumina brass casing 1 and the plate 3 is inserted into a recess in the holder 1 which is somewhat under-cut as shown in the drawing. The plate 3 is then upset by pressure so as to edge of the holder is then spun over the edge of the plate 3 to hold it in place as shown in Fig. 4.

For the drawing of copper, a die made as above described lasts sixty times as long as the ordinary steel die. Of course, metals other than copper, such as steel, nickel, or even tungsten may be drawn both cold and hot through my improved 'die.

When making articles of oxids other than aluminum oxid, the process is essentially the same, except that the final firing temperature should in all cases be below the melting point of the respective material.

I mean by the appended claimsto cover not only an article consisting of the oxid of aluminum but also of the described equivaflow into the undercut portion and-the ,ing pf an oxid of lents, namely, the oxids of beryllium andv titanium.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. An article of manufacture consisting of aluminum oxid sintered in its approxi mate shape ata temperature just below its melting point to a dense, amorphous state in which 1t is capable of taking a high polish and withstanding sudden changes of temperature without cracking. I

body consist- 2. A' shaped wear-resisting aluminum sintered in its approximate shape to a strong, hard, structureless form capableof taking a high polish.

I ing of dense, opaque,-oxid of aluminum sintakes place, shaping the tered in its approximate shape devoid of crystalline structure and having a specific gravity of 3.8 to 3.9, and a hardness equal -to that of sapphire.

4.- The process which consists in com-pacting a refractory oxid with a binder, baking to a temperature at which slight sintering material mechanically and finally firing at a higher tempera-' ture below the melting'point at which complete sintering takes place.

' 3. A shaped wear-resisting body consist-- ture of about 1300 0., machining1 the material to its approximate final s ape and then firing to a higher temperature just below the melting point of the oxid whereby sintering to a dense, strong, structureless state is secured.

'7. The process which consists in compact:

ing aluminum oxid and gum tragacanth, baking toslightlysinter the material, shaping the same into desired form, and firing t a temperature of about 1800 to 2000 C. to sinter the' same into a dense, amorphous state.

In witness whereof, I have hereunto set my hand this 5th day of February, 1912.

CHRISTIAN DANTSIZEN.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

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