USRE25815E - Metallic compositions - Google Patents

Description

July 1965 M. HUMENIK, JR., ETAL 25,815

METALLIC COMPOS ITIONS 4 Sheets-Sheet 1 Original Filed June 22, 1959 cm 02mm 44.52 mmIoz 0m moo woo

SBHONI CINV I HVEIM MICHAEL HUMENIKJR DAVID MOSKOWITZ INVENTOR.

J M flaiu ATTORNEYS July 6, 1965 Original Filed June 22, 1959 CUTTING TIME- MINUTES M. HUMENIK, JR.. ET AL Re. 25,815

METALLIC COMPOSITIONS 4 Sheets-Sheet 2 SAE I045 BHN I63- I74 FEED-0.0lI"/REV. DEPTH 0F CUT- o.|oo spasm-e00 SFPM WEAR LAND -o o|o" COOLANT PERCENT MOLYBDENUM IN BINDER(2O MICHAEL HUMENIK,JR

DAVID MOSKOWITZ ,INVENTOR.

ATTORNEYS FIG. 2

July 6, 1965 M. HUMENIK, JR, ETAL Re. 25,815

METALLIC COMPOS ITIONS 4 Sheets-Sheet 3 Original Filed June 22, 1959 2 ON 2 mm 2 0w 2 Q GDDIZ him-m; m mmozi m0 wmfimommm m Ow Om ON VB SSENCIHVH MICHAEL HUMEN|K,JR. DAVID MOSKOWITZ INVENTOR.

ZZMMZ (9 ATTORNEYS July 1965 M. HUMENIK, JR. ETAL Re. 25,815

METALLIC COMPOSITIONS Original Filed June 22, 1959 4 Sheets-Sheet 4 o i v F.

m o E |-|J: LL E I 3 5 8 A 9 52' 5-. N .O Q o QF-I-U-I 2%315258 mm emu K, J N

Al I

2O CUTTING TIME MINUTES SHHONI -GNV I HVHM MICHAEL HUMENIK, JR. DAVID MOSKOWITZ INVENTOR.

A. 44 iii 3m) ATTORNEYS FIG.4

United States Patent Ofice Re. 25,8l5 Roissued July 6, 1965 25,815 METALLIC COMPOSITIONS Michael Humenik, Jr., and David Moskowitz, Wayne County, Micln, assignors to Ford Motor Company,

Dearhorn, Mich, a corporation of Delaware Original No. 2,967,349, dated Jan. 10, 1961, Ser. No.

322,048, June 22, 1959. Application for reissue May 21, 1964, Ser. No. 380,727

6 Claims. (Cl. 29-182.?)

Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

This invention is a continuation-impart of that described in application Serial No. 722,040, filed March 1 7, 1958, now abandoned.

This invention relates to hard, metallic compositions which are particularly suitable for cutting bits for machining metals at high speeds. These compositions are essentially compacts of titanium carbide together with molybdenum and a metal of the iron group, particularly nickel. The molybdenum may be added to the compact either as metallic molybdenum, or as a carbide of molybdenum, or a mixture of metallic molybdenum and molybdenum carbide. These compacts have been perfected as a decided improvement upon the cemented tungsten carbide tool bits which now enjoy widespread commercial acceptance. This invention is related to a metallic composition which for tool bit purposes is a decided improvement on the metallic compositions taught in United States Letters Patent to Goetzel et al., 2,581,252, January 1, 1952; Goetzel et al., 2,694,007, November 9, 1954; Redmond et 211., 2,711,009, June 21, 1955; Goetzel et al., 2,752,666, July 3, 1956; Goetzel et al., 2,753,261, July 3, 1956, and the compositions described by Humenik and Parikh, The Journal of the American Ceramic Society, volume 39, Number 2, February 1956, pages 60, 61, 62 and 63.

To aid in an understanding of this invention, four figures of drawings have been presented in which:

FIGURE 1 is a graph in which the abscissa represents the amount of metal removed in a cutting operation and the ordinate represents the corresponding tool wear, and

FIGURE 2 is a graph in which the percentage of molybdenum in the binding alloy is laid out on the abscissa and the cutting time to a definite tool wear is laid out on the ordinate, and

FIGURE 3 is a graph in which the weight percentage of binding alloy is laid out upon the abscissa and the Rockwell A hardness on the ordinate, and,

FIGURE 4 is presented to demonstrate the difference in performance between cutting tools based upon solid solutions of molybdenum carbide in titanium carbide and cutting tools fabricated from mixtures of nickel, titanium carbide and molybdenum carbide, or from mixtures of nickel, titanium carbide and molybdenum.

A titanium carbide composition essentially free of oxides and nitrides having the following analysis was chosen as the base material.

Percent Free carbon 1.2 Combined carbon 19.2

Titanium 78.1

Iron 0.06

The size analysis of: this material as determined by Andraeson particle size analysis was CUMULATIVE PERCENTAGE OVERSIZE Percent 25 microns 0 15 microns 0 5 microns 0 2 microns 26.4 1 micron 49.5

The binding alloy was added as approximately five micron nickel and molybdenum powder. The metal powder was prepared separately by milling a seventy-five percent nickel, twenty-five percent molybdenum powder and fifty percent nickel, fifty percent molybdenum mixture from minus three hundred twenty-five mesh powder. When necessary small additions of minus three hundred twenty-five mesh metal powder were used to give a charge of the desired final composition. The compositions recited in the appended claims refer to the composition of the compact prior to any reactions which may occur during sintering.

The grinding operations were conducted in a stainless steel mill containing Hastelloy B balls, benzene being added to inhibit oxidation of the charge during the twenty-four hour milling period. After milling the henzone was evaporated and four percent wax binder dissolved in benzene was added. Upon drying the powder was pressed in a steel die at a pressure of about ten tons per square inch.

The cold pressed compacts were presintered in a hydrogen furnace at 1200" Fahrenheit for one hour to dewax the specimens. Final sintering was performed on an inert stool and in an inert ambient at 2500 Fahrenheit for one hour in an induction furnace. An absolute pressure of about 0.1 to 0.3 micron was maintained in the furnace although any suitable inert ambient will be satisfactory. Suitable inert ambieuts are dry hydrogen, argon or helium. The sintering temperature is, of course, a function of sintering time, the time being shortened as the temperature is raised. In any event the sintering temperature should not exceed 2700 Fahrenheit to avoid substantial grain growth. The time and temperature of sintering must be adjusted so that the grain size of the titanium carbide in the finished article is not substantially larger than that of the starting powder.

it is essential that the binding alloy contain at least ten percent of molybdenum to take advantage of the ability of this metal to cause alloys containing it to Wet the surface of the hard titanium carbide particles. Bearing in mind this limitation, it is possible to substitute either tungsten or chromium or alloys or mixtures of tungsten and chromium for a portion of the molybdenum.

FIGURE 1 clearly shows the superior performance of the cutting compositions taught by this invention as compared to commercially available cemented tungsten carbide compositions. The data presented in FIGURE 1 was obtained by cutting a log of SAE 1045 steel at a Brinell hardness of 163 to 174 with a feed of 0.011 inch per revolution and a depth of cut of 0.100 inch at a surface speed of 350 feet per minute. The two upper curves represent typical cemented tungsten carbide performance. The three lower curves were obtained using as a cutting bit a composition of 65 percent titanium carbide and percent binding alloy, this binding alloy being 70 percent nickel and 30 percent molybdenum. The powders were milled in a steel mill with steel balls for twenty-four hours under benzene. A wax lubricant was added and the powder was pressed in a steel die at ten tons per square inch. Dewaxing was carried out at 1290 Fahrenheit for one hour in hydrogen and final sintering was performed in vacuo (about 0.1 to 0.3 micron) at temperatures of 2450, 2500 and 2550 Fahrenheit for two hours. The hardness of the sintcred specimens ranged from R 90.0 to 91.0.

FIGURE 2 is presented to show dramatically the ettect of varying the amount of molybdenum in the binding alloy on the durability of the finished tool in machining tests. The data presented in FIGURE 2 was obtained in exactly the same manner and under the same circurnstances as those outlined above in connection with FIG- URE 1 except that the cutting speed was increased to 600 feet per minute. In each case the tool was operated until a land wear of 8.610 inch was observed. The binding alloys in these tools were fabricated from molybdenum and nickel. The binding alloy in each case compriscd 20 percent of the mass of the tool.

FIGURE 3 shows the hardness of the tool compositions as a function of the percentage of binding alloy in the tool composition at four different levels of molybdenum in the binding alloy. In addition, individual points indicate values at 45, 6t), and percent molybdenum in the binder.

The graph comprising FIGURE 4 clearly illustrates the contrast in properties between the cutting tools prepared from titanium carbide which is effectively free of dissolved molybdcnum carbide and similar tools prepared from titanium carbide containing substantial amounts of dissolved molybdenum carbide. Since the sintcring temperatures employed in the preparation of the compacts are high enough to permit the constituents of the compacts to come to equilibrium between the titanium, molybdenum and carbon, it would appear at first blush to be immaterial whether the mol elemental molybdenum, as int :1 solid solution of inolylnlcium c bide.

. can that t addition of niolyh. 1.. in ti tanium carbide trot dec while the addition of molybdenum as mum num carbide in cat the curve titaniur or as mo carbide produces URE 4 of the din compact prepared front and nickel. Curve 2 depicts the performance of a compact prepared from titanium carbide. hide and nicxcl while cum 3 is con t a bide compact produced from a solid. clulion of nio denum carbide in titanium carbide.

The composition. preparation and testing detail; of the tools depicted in FIGURE 4 follow:

(I) TiC+ltlhio t iONi l O,v

(2) sllTif l ltloltlosC-t-lllbli (3) il'fiCfldfiMo f) solid solution+lONi cntbicle.

free carbon The solid solution carbide was prcnared by mi parts TiC and like parts li'lo C, compacting the n. and sintcring for one hour at lllliltl C. in a J it crucible un-lcr vacuum. X-rv 3 analysis of the sintered slug showed only one phase to be present, i.e., the TiC/Mo C solid solution. The sintered slug was crushed and milled under benzene in a stainless mill to a fine particle size (less than five microns). The milled solid solution powder was then leached repeatedly in a dilute sulphuric acid solution until substantially all milling impurities were removed.

The preparation of the tool composition was similar in powders for 48 hours i r. lla'liciloy cc waxing ering in Ii balls, add. the triples in h,

for one h The :eintcr 'l s F. were ground the form of tools. :t'td s ndard in.

lcplh of cut 01" cutting :rpccd The tits as shown in Fi l]- that similar cutti.

tamed whe lybdcnnm is add as the metal r carbide, although the addition of molyb illllil ber oi the biarnng alloy is nickel. However, non group me cite, or their alloys, may be em out departing", from the snirit of the invention.

' ty of the d witht t free of detrimental quot an, ar cc: ntrally of ti 1am ear hie and a mol bdc .ll con aining i binding alloy, said hi: ling alloy con s gntially of twenty-five percent to seventy perc ol :1 ...atcrial ccted from the class consisting of molybdenum, molybdenum carbide and mi tilt of molybdenum and in denurn carbide and an alloying metal selected from the group consisting of iron, cobalt, nickel and alloys thcreofi said titanium carbide being essclrtfm'ly free of dissolved molybdenum and molybdenr'm carbide and said bll in alloy in turn comprising ten to fifty percent of the ma; of the compact, the for!!! ram'y (fem-m manner of H 5 compact not are edan 13% of the mass of the compact.

2. A hard sintc d compact particularl t suitable for cutting tools and cxlnbitnc a ha. vncss of at least on the Rockwell A sca e, Ll con ing free of detrimental quantities of nit ides and and consisting vlcnnm con- "iining binding a loy. said binding: al oy consi .inc csscn tially of twenty-five percent to seventy percent it material selected from the class consisting of molybdenum. molybdenum carbide and mix'tures ol ntc i tienurn and molybdenum carbide and an alloying metal lected from the group consisting of iron, cobalt, nickel and alloys thereof, t 1 titanium carbide hcr'fri; essentially free drsrolrcd nmlv/nlcmmz (Jrm' i.' l) \l (l'[ilFJF)I cart-bide and said binding al oy in turn coniprr ten to filtv percent of the mass of the com ct, the mm! mm; n content of the compact not arc-ceding 13% of the compact.

3. A hard sintcred compact particularh suitable for cutting tools, said compact being free of de .ntcl quan titles of nitrides and :rides and consisting e sentially of titanium carbide and a molybdenum containing bindinw. alloy, said binding alloy consisting essentially of twent five percent to seventy percent of a matcri: lccted froin the class consisting of molybdenum, molybr um carbide and mixtures of molybdenum and mat; and an alloying metal selected from the gr of iron, cobalt, nickel and alloys thereof, said titanium curr'rr'de being essentially free of (limo/awn molybdenum and molybdenum carbide and said binding alloy in turn comprising ten to fifty percent of the mass of the compact, said sintering being carried out in an inert ambient at a temperature not substantially above about twentysevcn hundred degrees Fahrenheit, the total molybdenum content of the compact not exceeding 13% of the mass of the compact.

4. A hard, sintcrcd metallic compac particularly suitable for cutting tools, said compact lasing free of detriientul quantities of nitrides and oxides and consisting esscntinlly of titanium cur nun: containing .witlc and n molyl binding alloy. said binning alloy consisting essentially of significantly in excess of twcntylive percent to seventy percent of a material selected from the class consisting of molybdenum, molybdenum carbide and mixtures of molybdenum and molybdenum carbide and an alloying mctnl selected from the group consisting of iron, cobalt, nickel and alloys thereof, said titanium carbide being cs- SBI'lllGll) free of dissolved molybtlelzrmz and molybdenum carbide and said binding alloy in turn comprising ten to fifty percent of the mass of the compact, the total molybdenum content of the coiizpact not exceeding 13% 0 the mass of the compact.

5. A hard sintered compact particularly suitable for cutting tools and exhibiting a hardness of at least 90 on the Rockwell A scale, said compact being free of detrimental quantities of nitrides and oxides and consisting essentially of titanium carbide and a molybdenum contnining binding alloy, said binding alloy consisting essentially or" significantly in excess of ttventydive percent to .eventy percent of a material selected from the class consisting of molybdenum, molybdenum carbide and mixtures of molybdenum and molybdenum carbide and an alloying metal selected from the group consisting of iron, cobalt, nickel and alloys thereof, said titanium carbide being essentially free of dissolved molybdenum and molybdenum carbide and said binding alloy in turn comprising ten to fifty percent of the mass of the compact, the total molybdenum content of the compact not exceeding 13% of the mass of the compact.

A hard sintcred compact particularly suitable for cutting tool. aid Clill.ttClI being free of detriment-til quan- .md oxides and consisting cssentislly of rnitnn Ci'lil l and n molybdenum containing binding I. said binding alloy consisting essentially of significantly in excess of twenty-five percent to seventy percent of a material selected from the class consisting of molybdenum, iOl}l.lLlCill.ill1 carbide and mixtures of molybdenum and molybdenum carbide and an alloying metal selected from the n'oup consisting of iron, cobalt, nickel and alloys lhcrcof. mill tiimzimn carbide being essentially free of dissolved molybdenum and mt'Jlybdent m carbide and said binding nlloy in turn comprising ten to fifty percent of the mass of the compact, said sintering being carried out in an inert ambient at a temperature not subs itinlly above about twenty-seven hundred degrees Fahrenheit, the total molylm'ennm content of the compact not exceeding 13% of the mass of the compact.

OTHER REFERENCES Powder Metallurgy Bulletin, Volume 4, No. l, Yonkers, NY. January 1949. Page 13. TN695 P56.

CARL D. QUARFORTH, Primary Examiner.

BENJAMEN R. PADGETT, Examiner.

Claims (1)

1. A HARD SINTERED METALLIC COMPACT PARTICULARLY SUITABLE FOR CUTTING TOOLS, SAID COMPACT BEING FREE OF DETRIMENTAL QUANTITIES OF NITRIDES AND OXIDES CONSISTING ESSENTIALLY OF TITANIUM CARBIDE AND A MOLYBDENUM CONTAINING BINDING ALLOY, SAID BINDING ALLOY CONSISTING ESSENTIALLY OF TWENTY-FIVE PERCENT TO SEVENTY PERCENT OF A MATERIAL SELECTED FROM THE CLASS CONSISTING OF MOLYBDENUM, MOLYBDENUM CARBIDE AND MIXTURES OF MOLYBDENUM AND MOLYBDENUM CARBIDE AND AN ALLOYING METAL SELECTED FROM THE GROUP CONSISTING OF IRON, COBALT, NICKEL AND ALLOYS THEREOF, SAID TITANIUM CARBIDE BEING ESSENTIALLY FREE OF DISSOLVED MOLYBDENUM AND MOLYBDENUM CARBIDE AND SAID BINDING ALLOY IN TURN COMPRISING TEN TO FIFTY PERCENT OF THE MASS OF THE COMPACT, THE TOTAL MOLYBDENUM CONTENT OF THE COMPACT NOT EXCEEDING 13% OF THE MASS OF THE COMPACT.

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