US3421888A - Copper alloy - Google Patents

Description

United States Patent 3,421,888 COPPER ALLOY Matti J. Saarivirta, Marquette, Mich, assignor, by mesne assignments, to Calumet & Hecla Corporation, Evanston, 11]., a corporation of Delaware No Drawing. Filed Aug. 12, 1966, Ser. No. 571,983 US. Cl. 75-159 3 Claims Int. Cl. C22c 9/00 This invention relates to a copper base alloy having good responses to precipitation hardening and cold workmg.

Copper alloys of high tensile strength, hardness and good electrical conductivity are well known in the art. Thus, alloys of this type are the copper-beryllium alloys and particularly copper-beryllium-cobalt alloys. These, however, are expensive so that the cost limits their use.

One of the features of this invention is to provide a copper base alloy having good responses to precipitation hardening and cold working to produce an alloy of high tensile strength, good electrical conductivity and excellent hardness that is considerably cheaper than previous alloys having these characteristics, the new alloy containing, by weight, about 0.41.5% chromium, about 0.30.9% titanium, about 0.10.8% nickel, about 0.020.l6% phosphorus, the remainder being substantially oxygen free copper, in which the weight amount ratio of nickel to phosphorus is about of nickel to 1 of phosphorus and the weight amount of titanium is about 1-1.7 times the sum of the amounts of nickel plus phosphorus.

The copper of the alloy contains the lowest amount possible of oxygen. This can be either initially oxygen free copper which is ordinarily produced in a reducing atmosphere, an inert atmosphere or a vacuum or it can be copper that has been deoxidized with such well known deoxidizers as phosphorus, silicon, lithium, calcium, calcium boride or the like which combine with the oxygen in the copper to eliminate it substantially completely.

The alloys of this invention have been found to be useful in manufacturing resistance welding electrodes as well as electrical and electronic components generally.

The presence of the chromium in the alloy increases the response of the alloy to precipitation hardening and gives increased hardness and tensile strength. The titanium also appears to increase the hardness of the alloy.

The new alloy may be fully annealed by solution heat treatment in a non-oxidizing atmosphere, either reducing or inert. This is a well known procedure in which the alloy is heated to a temperature between about 9001000 C. and then cooled by rapid quenching. The solution heat treated alloy of this invention responds excellently to precipitation or age hardening. This is generally done by reheating the quenched alloy for one hour or more at about 300-600 C. for the generally one or more hours of aging. In general, the higher the temperature of heating the shorter the aging time. In practice excellent precipitation hardening conditions have been to reheat to about 500 C. for about 2 hours. Such precipitation hardening strengthens the alloy while at the same time increasing the thermal and electrical conductivity.

The strength and hardness of the alloy can be further increased by the customary cold working which is performed in the usual manner. This cold working may be an intermediate step between the solution heat treatment and the precipitation hardening or it may be done after precipitation hardening, as desired.

Thus the copper-chromium-titanium-nickelaphosphorus alloys of this invention are highly precipitation hardenable and give excellent response to cold working. Heat treatment at 500 C. after solution annealing at 1020 C. results in an ultimate tensile strength of 80,000-83,000 p.s.i., 77-83 Rockwell B hardness and 55-65% IACS RIG electrical conductivity. When cold worked to a 15% reduction in area, the tensile strength is 90,000-97,000 p.s.i., hardness 88-92 and the electrical conductivity is not changed. Very similar properties are obtained by solution annealing, 60% cold reduction and heat treating. The new alloys can be easily melted and cast without difficulty providing the usual protective atmosphere is maintained.

The following tables set forth various alloys coming within the invention, their treatments and their properties. In each example the copper was melted first, then the chromium added and completely dissolved in the copper melt, then the titanium dissolved in the copper melt and finally the nickel and phosphorus added and the entire molten alloy mixed to a homogeneous condition. 500-1000 gram castings were then made at casting temperatures of 1110- 1200 C. in graphite and cast iron molds with each 1000 gram casting being about 0.75 inch in diameter by 12 inches long and the 500 gram castings being about 0.75 inch in diameter by 6 inches long. During the melting and the casting the melts were maintained under non-oxidizing conditions in that they were surrounded by an atmosphere of an inert gas, with argon being especially preferred for this purpose.

The following tables present various examples of alloys within the invention and their characteristics. Thus, in the following Table No. 1 there is shown the effect of various amounts of nickel and phosphorus forming nickelphosphide on the properties of basic copper-chromiumtitanium alloys. The other tables record the effects of various treatments on the alloys of this invention.

TABLE 1 Heat treated Elec. cond.,

VPN Rb percent IACS Solution annealed Hard- Elec.

ness cond., VPN percent IACS Percent Example Hardness Ni P Copper Alloy Containing 1% Chromium and 0.3% Titanium Copper Alloy Containing 1% Chromium and 0.4% Titanium Copper Alloy Containing 1% Chromium and 0.5% Titanium Copper Alloy Containing 1% Chromium and 0.9% Titanium TABLE 4 Efiect of cold working after aging. Cast specimens hot forged to 0.45 inch with 50% reduction, solution annealed at 1,020 C. for 30 minutes,

. 02 67 1' 1'0 81 24 04 74 1 35 21 guonched, aged at 500 C. for 2 hours and cold worked various amounts 2 16 152 32 g 1n cross section] 08 16 106 85 "0 1 99 19 145 81 0 Solution annealed Cold worked after aging 1% 22 17 100 84 43 and aged 1 138 23 81 55 Alloy Hardness Elee. Percent Hardness Elec. cond col cond.,

VPN Rb percent reduct. VPN Rb percent IAC 10 E 40 140 78 58 7 155 82 57 X. TABLE 2 140 78 58 19 164 86 57 [Eilcct of heat treating temperatures on the hardness and electrical conductivity of the Cu-Cr-Ti-Ni-P alloys. The cast specimens were EL 29 134 2 9 164 82 61 solutioin tannealed tat 1,020 011M232 minutes, quenched, and heat 134 75 19 155 86 61 t at i s m e l t s s m e e p H 2: 1 E d Ex. 38 155 81 4o 9 172 no 49 condition m 655 fi' fl Example 40C0pper alloy containing 1% chromium, 0.55% titanium,

VPN Rb 0.28% nickel and 0.032% phosphorus.

Example 2.Copper Alloy Containing 1% Chromium, 03% Titanium, 0.2% Nickel and 0.04% Phosphorus N0 aging 48 28 2O Aged at 450 C. 110 65 59 Aged at 470 C 130 74 05 Aged at 500 C 145 70 00 Aged at 520 C. 126 09 00 Aged at 550 C 117 64 72 Aged at 050 C 83 35 04 Aged at 700 C .1 03 (i0 TABLE 5 Example 29.Coppe A1103: Containing 11% C hromiu1n, -7% Titani fifiperltligssoiviiligssol lfigoilggiielzggdiggleltilndvieigldvgagfil Nickel and 008% hobphorus annealed at 1,020 O. for 20 minutes, quenched, heat treated at 500 C. No aging 53 40 29 for 2 hours, and cold drawn after heat treatment to 0.116 inch with Aged at sod 6.1: 148 81 a1 15% reducnm ma] 0 i gg g 30 Tensile Elong, Hardness Elce. g at 0 :1: 57 Ex. Condition strength, percent cond, d m C 74 23 p.s.1. 111 2 111. VPN Rb percersrt 2. S01. annoaled. 38, 000 30 52 47 27 Aged 79, 000 10 141 60 35 Cold drawn 82, 000 0 107 -00 00 I 0 S01. annealed... 43,000 30 51 48 28 TABLE 3 Aged 82,000 13 145 78 e4 [Eilect of Serious solutlion all ill tliillllg temperatures on tllietpropertiesl (at Gold 000 5 8790 63 the Cu r-Ti-Ni-P a loys. 1e cast specimens were so u ion annea e at the temperatures indicated for 30 minutes, quenched, and aged g -g gs 2, g;

0 at 500 for 2 1mm] 40 Cold drawn 231000 5 180 88-92 58 Temperature Hardness Elec. cond.,

' 128288. 21: 211 e a 2 a Cold drawn 92, 000 5 171 88-90 60 S-:33 2 900 106 48 71 29. s01. annealed... 43, 000 23 53 58 25 p 88 106 Aged o 000 13 150 so 58 $1111: 3 62 45 cold drawn es, 000 5 180 88-92 68 Example 20 900 107 59 64 Example 38 e00 124 so 44 21 42, g; Example 2 925 no 57 Cold drawn--." 901000 5 183 88-21 47 Example 8 025 61 Example 15 e25 108 60 5e 2? g? Example 21 025 03 61 5O 5 180 884,2 55 Example 20 025 100 63 65 I Emmple 43 Example ll-Copper alloy containing 1% chromium, 0.7% titanium, Example 2 50 114 G3 72 0.4% nickel and. 0.08% phosphorus. Example 8 950 118 60 08 Example 15. 950 117 05 65 Example 21... 950 124 08 02 55 Example 29 950 124 07 65 Example 38 050 134 74 41 Example 2 975 121 66 71 Example 8.- 057 124 71 60 Example 15. 075 124 09 61 Example 21.-- 075 132 72 62 Example 29 075 72 e4 60 Example 38 975 144 77 40 Example2 1 000 125 73 71 TABLE 6 Example 8: 1:000 134 73 65 The hardness and electrical conductivity properties of the alloys cold Example 15. 1,000 134 73 03 worked and aged after solution annealing. Cast specimens were hot Example 21. 1, 000 134 74 62 forged 50%, solution annealed at 1,020 0., cold worked various amounts Example 20. 1,000 132 2% 65 and then aged at 500 C. for 2 hours] Exam e38 1 000 14 p Percent Cold worked condition Cold worked and aged Example 2 1, 020 70 69 cold re- Example 8 1,020 145 78 66 Example duct. in Hardness Eleg. Hardness Eleg. Exam le 1.). 1 020 140 77 64 cross con con mangle 21. 11020 151 so 62 sect. VPN Rb percent VPN Rb percent Example 29 1,020 148 82 01 IACS 1 Example 38 1,020 100 84 43 70 40 16 78 44 25 80 58 Example 2 1,040 143 7e 70 34 106 58 24 190 83 80 Example 8 1, 040 140 79 06 40 110 61 24 140 85 61 Example 15. 1, 040 142 77 04 Example 21- r 1,040 147 82 03 38 10 80 51 18 88 55 Example 20- 1, 040 146 80 00 34 112 05 20 173 80 55 Example 38 1, 040 143 79 44 75 46 120 66 19 181 91 55 TABLE 7 [Efiect of heat treating temperatures on the properties 01 the cold drawn wires of Cu-Cr-Ti-Ni-P alloys. The 0.128 inch diameter wires were solution annealed at 1,020 C. for 20 minutes, quenched, cold drawn to 0.081 inch with 60% reduction in area and heat treated at various temperatures'for 1 hours] Tensile Elong., Hardness Elec. Example Condition strength, percent VPN cond.,

, p.s.i. in 2 percent inches IACS 2 C'old drawn- 64,000 3 124 26 Aged at:

9 1. Cold drawn 64,000 3 124 26 Aged at:

350 O 66,000 3 120 32 400 C ,000 6 138 41 450 C 83, 000 8 170 56 475 C 000 8 171 61 500 C 90, 000 9 169 65 525 C"... 85,000 9 165 67 550 C ,000 8 153 67 Cold drawn... 67,000 3 128 23 Aged at:

29 Cold drawn". 66,000 3 124 26 Aged at:

350 C 65,000 4 120 29 400 C- 000 8 138 39 450 C..." 85, 000 10 163 54 475 C... 000 10 174 60 500 0..." 90,000 10 169 63 550 C.. 74, 000 8 153 65 38 Cold drawn 67,000 3 126 Aged at:

350 000 4 133 24 400 O 70, 000 7 143 450 C... 91, 000 10 177 39 475 94,000 8 182 44 500 C 92, 000 9 180 47 550 C.... 92, 000 8 170 51 Tensile Elong., Hardness Elecl Example Condition strength, percent VPN cond.,

p.s.i. in 2 percent inches IACS 41 Cold drawn 69,000 123 22 Aged at: 350 0..... 70,000 4 134 26 400 C 74, 000 7 143 33 450 C-.-.- 88, 000 10 177 43 475 C 91-, 000 0 177 47 500 0---. 91, 000 9 174 52 550 C-.- 89, 000 11 165 53 00 0..... 73, 000 9 140 Having described my invention as related to the embodiments set out herein, -'1 is my intention that -the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

I claim:

1. A copper base alloy having good responses to precipitationhardening and cold working consisting essentially of: about 0.41.5% chromium, about ;0.30.9% titanium, about 0.10.8% nickel, about 0.020.16% phosphorus, and substantially. the entire remainder-a member of the class consisting of initially oxygen free and deoxidized copper, the amount ratio of nickel to phosphorus being about 5 of nickel to l of phosphorus and the amount of titanium being about 11.7 times the sum of the amounts of nickel plus phosphorus, the percentages and amounts being by weight.

2. The alloy of claim 1 precipitation hardened and cold Worked to produce in the alloy high tensile strength, good electrical conductivity and excellent hardness.

3. The alloy of claim '1 in which the amount of chromium is about 1%.

References Cited UNITED STATES PATENTS I 1,991,162 2/1935 Kroll 148-32.5 X 2,189,198 2/ 1940 Qomstock -164 X 2,362,007 11/1944 Hensel et al. 75--153 X 2,783,143 2/1957 Johnson et al 75164 X 3,162,529 12/1964 Doi 75-164 X FOREIGN PATENTS 120,469 10/1945 Australia.

CHARLES N. LOVELL, Primary Examiner.

U.S-. Cl. X.R. 75-153, 164

Claims (1)

1. A COOPER BASE ALLOY HAVING GOOD RESPONSES TO PRECIPITATION HARDENING AND COLD WORKING CONSISTING ESSENTIALLY OF: ABOUT 0.4-1.5% CHROMIUM, ABOUT 0.3-0.9% TITANIUM, ABOUT 0.1-0.8% NICKEL, ABOUT 0.02-0.16% PHOSPHORUS, AND SUBSTANTIALLY THE ENTIRE REMAINDER A MEMBER OF THE CLASS CONSISTING OF INITIALLY OXYGEN FREE AND DEOXIDIZED COPPER, THE AMOUNT RATIO OF NICKEL TO PHOSPHORUS BEING ABOUT 5 OF NICKEL TO 1 OF PHOSPHORUS AND THE AMOUNT OF TITANIUM BEING ABOUT 1-1.7 TIMES THE SUM OF THE AMOUNTS OF NICKEL PLUS PHOSPHORUS, THE PERCENTAGES AND AMOUNTS BEING BY WEIGHT.