US2826498A - Titanium-sulfur base alloys - Google Patents

Description

United States Patent 2,826,498 Patented Mar. 11, 1958 Another object of this invention is to provide valuable titanium-sulfur base alloys. 2,826,498 Still another object of this invention is to provide a N UM method for preparing titanium-sulfur base alloys, Where- TIT I SULFUR BASE ALLOYS in alloying additions are made in the form of sulfides. Harry P. Croft, Green Farms, Conn., assignor to Ken- Yet another object of this invention is to provide titanecott Copper Corporation, New York, N. Y., a corponium-sulfur base alloys having good properties of of New York strength, hot hardness, and heat treatability.

No Drawing Application October 21, 1955 Other ob ects and advantages of the mvention will be serial No. 542,105 apparent from the followlng detailed descrlptlon thereof. In general, this invention comprises titanium-sulfur 6 Clalmsalloys and titanium-sulfur base alloys and a method for preparing such alloys. I It has been found that highstrength, heat-treatable Thls invention relates to tltanlum alloys and more paralloys can be prepared by adding sulfur as a metal sulfide tlcularly to tltanlum-sulfur alloys and tltanium-sulfur base to tit nium metal. Similarly valuable binary alloys of l ys- It further relates to a method f providing rite titanium and sulfur can be prepared by adding titanium mum-Sulfur base 917 w e alloying additions are m sulfide to titanium metal in quantity sulficient to provide midi-106d Into the tltanlllm In the form of pp p binary alloys containing from 1 to percent sulfur. $u1fide$- 20 Table 1 below shows the effect of sulfur additions on In the past 1t has been shown that the addltlon of small th a a t hardness of commercial purity titanium. It amounts of Sulfur to Produces f y havlng will be apparent from the values listed that titanium-sulp j Strength d ductlllty Properties as P fur binary alloys possess high hardness rendering them Y unalloyedfltanlllm alloys are descflbed useful for the many applications Where such hardness is in y 6011611111113 pp Serial 7, fi important-for example in the tool industry. July 3, 1952, now Patent No. 2,721,797, granted October TABLE 1 25, 1955, of which this application is a continuation-inj part. It has now been found that useful alloys of titanium and sulfur may be produced through the addition 3 5: of sulfur in considerably higher amounts than were con- Composition, weight percent hardness templated in the prior art. Still further, it has been qg f found that extremely valuable ternary and quaternary titanium-sulfur base alloys can be produced and particu- 161 larly that such alloys can conveniently be prepared by 266 357 adding appropriate sulfides to titanium metal 1n an 387 alloying process. gig It is, therefore, an object of this invention to provide 762 useful binary alloys of titanium and sulfur containing in- 933 creased amounts of sulfur as compared with prior art 40 alloys. 1 Sulfur added as titanium sulfide.

TABLE 2 Yield strength, Elongation, Re- Bulfide p. s. 1. percent in duc- Vickers addition, Comp0sit1on,welght Tensile 1 inc tlon hardness Bend weight percent strength, in (10 kg. ductility, percent p. s. 1 area, load) T 0.1% 0.2% Uni-Total perofiset offset form cent None 100 '11 Cu 67,000 45,000 48,000 15. 31 53 176 0 101125 Ti0.80.2S 82,000 63,000 64,000 14 27 as 206 1 1.7 201123 T11.6ou0.4s 86, 000 65, 000 67, 000 12 21 29 224 2. 5 40u,s T13.2ou-0.ss 103, 000 77, 000 79, 000 12 17 21 247 4. 0 GOunS 'Ii-4.80u1.2S 114,000 34, 000 as, 000 11 13 17 272 5.0 ICIzSs Ti-0.530r-0.478 000 52, 000 63, 000 14 23 210 1. 8 20MB: Ti1.05Cr0.95S 93, 000 000 76, 000 12 20 31 219 2. s wits; Ti-2.1Cr-1.9S 108, 000 90, 000 92, 000 7 7 7 253 19. 3 was Ti-0.63Fe0.368 84, 000 ,000 60,000 15 27 34 202 1. 5 2FeS Tl-1.27Fe-0.73S 99, 000 70, 000 72, 000 14 22 31 232 1. s 4FeS T1-2.55Fe-1.45s 116,000 92,000 ,000 9 9 12 279 5.2 lMosi Tl-0.6Mo-0.4S 85, 000 59, 000 70, 000 15 28 44 219 2. 2 ,2M0s2 Ti1.2M60.ss 94,000 31,000 84,000 11 20 37 240 4.6 lPbS 'll0.86Pb-0.14S 73, 000 000 59, 000 13 2s 37 202 1. 9 2Pbs T1-1.73Pb0.27S 89, 000 68, 000 70, 000 12 26 37 233 1. s 4PbS T13.46Pb-0.54S 100,000 22, 000 33, 000 11 21 33 291 2. 6 ,6Pbs Ti-5.19Pb0.81S 110, 000 000 93, 000 11 18 25 302 2. 6 lens Ti0.79S11-0.21S 000 55, 000 55, 000 16 29 191 1. 8 2sns T1-1.5ssn0.42s 77, 000 58, 000 59, 000 12 23 31 202 1. 9 4311s Ti3.16S11-0.84S 000 65, 000 66,000 11 20 30 221 1. 9 1Mns Ti-O.63Mn-0.37S 79, 000 59, 000 000 15 24 38 193 1. 3 2M11S Ti1.25Mn0.76S 92, 000 63, 000 69, 000 14 24 29 215 2. 2 4M11S Ti-2.5Mn1.5s 110,000 91,000 91,000 5 5 s 1253 4.9 1W8; 'li-0.76W0.24S 88, 000 66, 000 68, 000 15 32 43 193 0. s 2W8: Ti1.52W-0.48s 99, 000 79, 000 32, 000 14 22 39 219 2. 3 0.5111281 T1-0.20A10.30s 85,000 ,000 65,000 14 30 39 197 l 1.7 1111,88 Ti0.39A1--0.61S 000 72, 000 so, 000 14 23 37 236 1. 7 2111133 Ti0.78A1-1.22S 131, 000 113, 000 115, 000 13 16 17 302 5. 7 1Tasi T1-0.74Ta0.258 000 57,000 62, 000 3 40 212 2. 3 2111511 Ti-1.4 8Ta-0.525 39, 000 61,000 66,000 6 10 33 232 3. 1 er s, Ti2.521a0.78S 96,000 73,000 73,000 6 9 31 238 2.4 was, Ti-2.96Ta"-1.04S 102,000 75,000 80,000 6 7 20 262 6.1

.600" C., held at 600 C. for one hour, and air cooled. Specimens tests were approximately 0.040 inch thick.

The reduced section of tensile specimens measured 0.25 inch by 1.25 inches.

Titanium-sulfur base alloys prepared as mentioned above have also been found to possess improved hot hardness values as compared with unalloyed titanium metal. Table 3 above lists hot hardness values for such alloys and for temperatures of 300 C., 400 C., 500 C., and 600 C. Values listed in Table 3 were obtained during tests conducted under a vacuum of less than microns using a load of 730 grams and an indentation time of seconds.

Table 4 below shows bend ductility and hardness values for titanium-sulfur base alloys after quenching from tem- TABLE4 S lfid Bend ductility, T, and Vickers hardness, VHN, after quenching trorn- 11 0 addition, Composition, weight weight percent 700 C 760 O. 810 O. 870 O. 930 0. percent VHN T VHN VHN T VHN T VHN T None 100 T1 181 0 184 0 182 0 189 0 214 0 111181 Ti0.48s 226 1.7 244 2.5 234 1.7 252 2.5 881 9.8 10u5s Ti0.8Cu-O.2S 216 2.8 218 3.1 226 4.8 268 1.6 297 2.5 2Ou2S T11.6Gu0.4s 236 4.6 237 4.5 238 2.3 273 6.1 812 4.6 401.128 Ti-3.2C110.8S 259 6.4 286 5.8 325 6.1 290 17.8 398 19.7 GCllzS T14.8cu-1.2s 284 8.9 287 17.4 384 17.8 349 17.8 437 17.4 101253 Tl-0.530r-0.47S 199 1.8 215 1.7 225 1.8 249 1.7 251 1.5 20128 Ti-1.05Cr0.95S 284 2.8 243 4.6 261 4.7 299 17.8 334 18.3 lFeS Tl0.63Fe-0.36S 224 1.7 230 1.6 237 4.9 246 2.5 248 4.9 2FeS Ti1.27Fe0.73S 230 4.9 258 2.5 299 4.7 818 4.4 445 18.8 lMoS: T10.6Mo0.4s 218 1.5 216 1.1 225 1.5 252 2.2 263 1.5 2MOSz Ti-1.2Mo-0.8S 242 2.2 252 2.1 276 2.2 269 13.2 326 19.2 111 1118 Ti-0.63Mn0.37S 196 0.8 197 1.7 209 0.8 221 1.4 224 1.7 2MnS Ti1.25Mn0.76S 218 1.8 242 1.7 258 2.5 251 2.7 266 1.7 4MnS Ti 2.5 Mn1.6S 266 5.1 294 9.6 348 5.1 418 18.3 357 19.6

TABLE3 Sulfide Vickers hardness, kgJmm at addition, Composition, weight weight percent percent 300C. 400C. 500C. 600C.

peratures of 700 C., 760 C., 810 C., 870 C., and 930 N 100 T1 101 82 61 38 C. ecimens were held at tem erature for one hour and 101118 T10.80u-0.2s 148 117 91 56 h Sp h d p 28mg r 1-1.6 u0.4 157 1:8 t en Water (111mlc f If b u 112 164 1 a rom titanium-su ur ase a o s ex- 6Cu1S ll4.80u-1.2S 166 152 116 61 .S prep y 1 Ti 0 53C 0 47 120 9g 76 42 h1b1ts outstanding propertles. Table 5 llsts mechamca 2017s; Ti1.05Cr0.95S 133 117 89 50 u er'als ions, TFMOPLQS 168 137 104 63 propert1es of several t1tamum s lfur base sheet mat 1 v ee s, Ti 3 15(} 2 g5S 1 g 149 115 68 and also mcludes, for comparison, mechanical properties lFeS Ti.063Fe-0.36S 107 81 67 38 mes TFLWFeAmBS 139 118 83 M of some correspondmg titanium alloys without the suliide 4 15 68 %-2.5 5 e1.45s 169 18g additions. The T1-Mo-V-S alloys 1n particular exhibit 0 1 -0.6 o-0.4S 140 0 zMoSg Ti 1'2M0 0 8S 149 124 85 46 outstanding properties. For the alloys m Table 5, sultur ggg T1-1.78Pb-0.27s 116 68 was introduced 1n the form of M08 The stabilizing Pbs 3Z3 1 33 54 treatment consisted of holding the specimen at 700 C. 4SnS Ti3.16Sn0.84S 126 91 70 50 1 coolin to 600 C. holdin for one lMnS Ti0.63Mn-0.37S 101 76 43 for /2 hourufumaw g g gM S 170 137 100 49 10 hour at 600 C., andan coollng. The quenched and 4Mns Ti2.5Mn1.5S 177 97 45 H lwsg Ti ol7fiw o 24s 103 85 64 39 V aged spec1men was helgl at 730 C. for two hours, water gvgi 1 1 .52 7 0.48s 148 114 i8 quenched, held at-SOO C. for 16 hours, and then an 1 1 1- .26 0.30s 108 81 1 A1283 125 106 79 51 cooled. The results of tests at elevated temperatures 2411s TlO.78Al-1.22S 131 101 64 (480 C.) show the strengthening effect of the sulfide 7 additions. Y

TABLE 5 A. SPEOIMENS TESTED AT ROOM TEMPERATURE Yield strength, Elongation, per- I Tensile p. s. 1. cent in 1 inch Reduc- Vmkers Bend Composition, weight Condition of strength, tion in hardness ductility,

percent material tested p. s. 1. area, kg. T

0.1% 0.2% Uni- Total percent load) offset oflset form Ti-4Mo Stabilized 85, 000 60, 000 66,000 8 39 215 1. 4 'Ii4Mo S 00 68, 000 73, 000 6 11 27 240 1. 4 Tl-BMo 76, 000 83, 000 6 9 17 236 2. 2 Tl-8M0%S 79, 000 85, 000 4 6 22 258 4. 2 Tl=5Gr-1.2Mo0.8S 113,000 115, 000 11 16 27 264 7. 6 1-i- 5l[-1. 2M0-0.8S 130, 000 113, 000 119, 000 8 8 10 281 14. 3 'Ii5V1.2Mo-0.8S.- Quenche and aged- 150,000 115, 000 125, 000 7 11 19 325 2. 9

SPECIMENS TESTED AT 480 C.

Stabilized TABLE 6 Average Grain Diameter, mm. At Temperature, C.

Time at Temperature,

Hours 750 900 In view of the above disclosure it will be apparent that new and useful titanium-sulfur alloys and titaniumsulfur base alloys have been discovered, together with a method of preparing such alloys. Binary alloys of titanium with from about 1 percent to about 20 percent sulfur have been shown to possess improved and desirable hardness properties. Titanium-sulfur base alloys prepared by the addition of sulfides to the titanium metal have been shown to possess good strength and hot hardness properties and to be heat treatable. It has been shown that the effect of sulfur added as a metal sulfide is to impart strength, hot hardness, and heat treatability. Titanium-sulfur base alloys containing from about 0.2 percent to about 20 percent sulfur have been found to possess these desirable strength, hot hardness, and heat treatability characteristics. Alloying metals, added as sulfides, and present in the alloy in amounts from about 0.2 percent to about 10 percent, provide alloys having these same desirable characteristics. Indeed alloying metals in amounts up to 30 percent provide useful alloys as illustrated in Table 7 below, showing the effect of Mes additions on the as-cast hardness of high-purity titanium.

TABLE 7 M08; addl- Ascast tion, Composition, Vickers weight weight percent hardness, percent 10 kg. load 0 Unalloyed 100 1. 7 1Mo0.7S 207 8. 4 5M03.4S 405 16. 8 10Mo-6.8S 540 50. 3 30M0-20.3S 795 it has been further shown that the addition of sulfur, as a sulfide, retards grain growth. While it is true that such grain refining eifect can be obtained with other elements, carbon, for example, because of the lower solubility of sulfur in titanium, this eflect can be obtained at lower sulfur contents than with other refining elements.

The method herein disclosed for preparing titaniumsulfur base alloys, i. e., the addition of sulfur as a sulfide, has a number of advantages, aside from the excellence of the product so obtained. For instance, by this method it is possible to alloy the more volatile metals with titanium by adding such metals as sulfides. A good example of such a metal is lead which may be alloyed with titanium by adding it as lead sulfide (PbS) to the titanium metal.

T itanium-sulfur base alloys having useful and valuable properties have been prepared by adding sulfur as a sulfide such as titanium sulfide, copper sulfide, chromium sulfide, iron sulfide, molybdenum sulfide, manganese sulfide, lead sulfide, tin sulfide, tungsten sulfide, aluminum sulfide, and tantalum sulfide. The exact manner in which alloys have been prepared by sulfide addition is illustrated by the following example:

Example Titanium-sulfur and titanium-sulfur base alloys were prepared by melting in an inert tungsten-electrode arc type furnace. After charging a mixture of titanium and metal sulfide on a water-cooled copper hearth, the furnace was evacuated and flushed with argon several times. Arc melting was done with 250 to 350 amperes of current, after evacuating once again to a static argon pressure of from 15 to 20 centimeters of mercury. The resultant ingot was inverted and remelted several times until homogeneous. During melting, the metal sulfide is reduced, the metal alloying with titanium, and the sulfur combining with titanium to form titanium sulfide.

A titanium-sulfur base alloy of any composition may be prepared by charging an additional amount of alloying metal or metals together with the titanium and metal sulfide. in this manner, any number of ternary, quaternary, and more complex titanium-sulfur base alloys may be prepared which will consist of a matrix of titanium alloy and dispersed titanium sulfide particles.

It will be understood, of course, that useful titaniumsulfur base alloys can be prepared by the addition of metal sulfides other than those specifically mentioned in the examples and disclosure above. It is clear from the number of examples and from the data above that a general method of preparing these alloys has been discovered, such method comprising the addition of metal sulfides to titanium metal to produce titaniumsulfur base alloys. For example, the sulfides of vanadium, cadmium, nickel, cobalt, antimony, bismuth, mercury, silver,

zinc, calcium, indium, cerium, and other metals may be sulfur base metals.

New and useful alloys and a method for preparing them having been disclosed, it is desired to further define this invention according to the following claims.

What is claimed'is:

1. Titanium-sulfur base alloys consisting essentially of sulfur in amounts ranging from about 0.2 percent to about 20 percent, an alloying metal in an amount ranging from about 0.2 percent to about 10 percent, balance titanium, said alloys being characterized by improved strength and increased hot hardness, as compared with unalloyed titanium, and further characterized by being heat treatable.

2. Titanium-sulfur base alloys consisting essentially of sulfur in amounts ranging from about 0.2 percent to about 20 percent, an alloying metal in an amount ranging from about 0.2 percent to about 20 percent, balance titanium, said sulfur and said alloying metal having been 20 introduced into the alloy melt as a sulfide.

3. Alloys according to claim 2 wherein said sulfur and said alloying metal have been introduced into the alloy melt as a metal sulfide from the group consisting of copper sulfide, chromium sulfide, iron sulfide, molybdenum sulfide, manganese sulfide, lead sulfide, tin sulfide, tungsten sulfide, aluminum sulfide, and tantalum sulfide.

t 4. Complex titanium-sulfur base alloys comprising from about 0.2 percent to about 20 percent sulfur, at

least two alloying metals one of which has been added ,to the alloy melt as a sulfide, balance titanium.

5. Complex titanium-sulfur base alloys consisting essentially of from about 0.2 percent to about 20 percent sulfur, about 5 percent vanadium, about 1 percent to 1.5 percent molybdenum, said molybdenum having been added in the form of molybdenum sulfide, and balance titanium.

6. A complex titanium-sulfur base alloy consisting essentially of about 0.8 percent sulfur, about 1.2 percent molybdenum, about 5 percent vanadium, balance titanium.

References Cited in the file of this patent UNITED STATES PATENTS 609,467 Rossi Aug. 23, 1898 992,423 Hubbard May 16, 1911 1,089,773 Kraus Mar. 10, 1914 2,721,797 Croft Oct. 25, 1955 OTHER REFERENCES Goldhoff, R. M. et al.: The Influence of Insoluble 25 Phases on the Machinability of Titanium, published as A. S. M. 1952.

U, S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent No; 2,826,498 March 11, 1958 Parry 1Ea Croft It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Let oers Patent should read as corrected below.

Column 2, Table 2, under the heading "Composition, weight percent" first two lines thereof, for

read

(SEAL) Attest:

,KARL AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents

Claims (1)

1. TITANIUM-SULFUR BASE ALLOYS CONSISTING ESSENTIALLY OF SULFUR IN AMOUNTS RANGING FROM ABOUT 0.2 PERCENT TO ABOUT 20 PERCENT, AN ALLOYING METAL IN AN AMOUNT RANGING FROM ABOUT 0.2 PERCENT TO ABOUT 10 PERCENT, BALANCE TITANIUM, SAID ALLOYS BEING CHARACTERIZED BY IMPROVED STRENGTH AND INCREASED HOT HARDNESS, AS COMPARED WITH UNALLOYED TITANIUM, AND FURTHER CHARACTERIZED BY BEING HEAT TREATABLE.