WROUGHT COPPER-ZINC ALLOY, SEMI-FINISHED PRODUCT FORMED OF A WROUGHT COPPER-ZINC ALLOY AND METHOD FOR PRODUCING A SEMI-FINISHED PRODUCT OF THIS TYPE

Abstract

Wrought copper-zinc alloy for producing a semi-finished product with composition in wt. %: Cu: 58.0 to 66.0%, Si: 0.15 to 1,2%, P: 0.20 to 0.38%, Sn: up to 0.5%, Al: up to 0.05%, Fe: up to 0.3%, Ni: up to 0.3%, Pb: up to 0.25%, Bi: up to 0.1%, Te, Se, In: 0.1%, B: up to 0.01%, the rest Zn and impurities. The alloy has globular a-phase, B-phase and phosphide particles. The proportion of B-phase in the sum of -phase and -phase is 20 vol. % and max. 60 vol. %. In an area of 21000 m.sup.2 are 50 to 700 phosphide particles with an equivalent diameter of 0.5 to 1 m, 10 to 300 phosphide particles with an equivalent diameter of 1 to 2 m, and 3 to 45 phosphide particles with an equivalent diameter of 2 to 5 m.

Claims

1. A wrought copper-zinc alloy for production of a semifinished product in wire, tube or bar form, having the following composition in % by weight: Cu: 58.0% to 66.0%, Si: 0.15% to 1.2%, P: 0.20% to 0.38%, Sn: optionally up to 0.5%, Al: optionally up to 0.05%, Fe: optionally up to 0.3%, Ni: optionally up to 0.3%, Pb: optionally up to 0.25%, Bi: optionally up to 0.1%, Te, Se, In: each optionally up to 0.1%, B: optionally up to 0.01%, balance: Zn and unavoidable impurities, where the proportion of unavoidable impurities is less than 0.20% by weight, where the alloy has a microstructure composed of globular a phase, phase and phosphide particles, and the proportion of the phase in the sum total of phase and phase is at least 20% by volume and at most 60% by volume, where Si is present both in the phase and in the phase, where, in an area of 21 000 m.sup.2, there are 50 to 700 phosphide particles having an equivalent diameter of 0.5 to 1 m, 10 to 300 phosphide particles having an equivalent diameter of 1 to 2 m, and 3 to 45 phosphide particles having an equivalent diameter of 2 to 5 m, and where the proportion of the phase and the proportions of Si, P and Pb are chosen such that the alloy meets the condition 107 3782,25255.Math.[beta]64.1438.Math.[Si]115.18.Math.[P]30.7071.Math.[Pb]+0.017965.Math.[beta].Math.[beta]+24.6217.Math.[Si].Math.[Si]+66.7257.Math.[P].Math.[P]+0.542512.Math.[beta].Math.[Si]+1.36208.Math.[beta].Math.[P]+43.4012.Math.[Si].Math.[P]<37 where [beta] denotes the proportion of the phase in % by volume, [Si] the proportion of silicon in % by weight, [P] the proportion of phosphorus in % by weight, and [Pb] the proportion of lead in % by weight.

2. The wrought copper-zinc alloy as claimed in claim 1, wherein the Pb content is at least 0.02% by weight.

3. The wrought copper-zinc alloy as claimed in claim 1, wherein the ratio of the proportions by weight of P and the sum total of Fe and Ni is more than 2.0.

4. The wrought copper-zinc alloy as claimed in claim 1, wherein the proportions of Fe and Ni add up to not more than 0.1% by weight.

5. The wrought copper-zinc alloy as claimed in claim 1, wherein the P content is at least 0.26% by weight and at most 0.33% by weight.

6. The wrought copper-zinc alloy as claimed in claim 1, wherein Si content is not more than 0.35% by weight.

7. The wrought copper-zinc alloy as claimed in claim 1, wherein the Si content is at least 0.25% by weight.

8. The wrought copper-zinc alloy as claimed in claim 6, wherein the Cu content is at least 60.0% by weight and not more than 61.5% by weight.

9. The wrought copper-zinc alloy as claimed in claim 1, wherein the Si content is at least 0.50% by weight and at most 1.0% by weight.

10. The wrought copper-zinc alloy as claimed in claim 1, wherein the alloy has a hardness of at least 170 HV10.

11. The wrought copper-zinc alloy as claimed in claim 1, wherein the alloy has a tensile strength R.sub.m of at least 520 MPa.

12. The wrought copper-zinc alloy as claimed in claim 1, wherein the alloy has an grain size of not more than 21 m.

13. The wrought copper-zinc alloy as claimed in claim 6, wherein the alloy has an electrical conductivity of at least 12 MS/m.

14. A semifinished product in wire, pipe or bar form, made from a wrought copper-zinc alloy as claimed claim 1.

15. A component produced by machining and optional further processing steps from a semifinished product as claimed in claim 14.

16. A process for producing a semifinished product in wire, pipe or bar form, wherein the process comprises the following steps: a) melting a copper alloy having a composition as claimed in claim 1, b) continuously casting a tubular or bolt-shaped cast format with a water-cooled mold, c) hot pressing the cast format at a temperature of 620 to 700 C. with subsequent cooling at a cooling rate of 30 to 60 C. per minute within a temperature range from 550 to 350 C., d) optionally, heat treatment within a temperature range from 525 to 625 C. for 1 to 5 hours with subsequent cooling at a cooling rate of 20 to 40 C. per minute within a temperature range from 500 to 350 C., e) optionally, cold forming.

Description

[0063] The invention is elucidated in detail by working examples.

[0064] Samples No. 1 to No. 45 were melted in an induction kiln and then cast. The composition of the samples is documented in tables 1 to 4. Sample No. 16 represents the lead-containing reference alloy CuZn39Pb3. The samples were milled, homogenized at 650 C. for 1 hour and then hot-formed. In the cooling that follows after the hot forming, the cooling rate within the temperature range between 550 and 350 C. was about 40 C. per minute.

[0065] Samples No. 1 to No. 26, after hot forming, were machined and then cold-formed with a degree of forming of 20%. Samples No. 27 to No. 45, after hot forming, were annealed for 3 hours. The annealing temperature was about 600 C. for samples No. 28 and No. 35 to No. 41, while it was about 550 C. for samples No. 27, No. 29 to 34 and No. 42 to No. 45. The annealing was followed by cooling within the temperature range between 500 and 350 C. at a cooling rate of about 25 C. per minute. Thereafter, samples No. 27 to No. 45 were machined and subsequently cold-formed with a degree of forming of 20%.

[0066] In the final state, tensile strength R.sub.m and elongation at break were each determined from the tensile test, as were hardness (Vickers hardness HV10) and electrical conductivity. The longitudinal sections of the samples were examined by light microscopy. The area proportions of the phase and of the phase corresponding to the proportions by volume, and the grain size were determined therefrom. The light microscope images of the unetched samples were used for quantitative determination of the size distribution of the phosphide particles. Image details of dimensions 167 m126 m (corresponding to an area of 21 000 m.sup.2) were chosen, and these were evaluated in 1000-fold magnification by means of the ImageJ software. In this way, it was possible to discern individual particles and to determine the equivalent diameters thereof and the area thereof. The phosphide particles were classified by their equivalent diameter into the categories of 0.5 to 1 m, 1 to 2 m, 2 to 5 m andif presentgreater than 5 m.

[0067] Machinability was determined by means of a plane test. This was done using an insert with a contour that promotes chip breaking. The machining depth was 125 m and the plane speed 35 m/min. During the planing operation, the bending moment that acts on the tool was measured, and this was used to determine the average bending moment. The resultant chips were visually assessed and categorised by chip form. The chip form was assigned a chip form number according to the following list:

TABLE-US-00001 Chip form number Chip form 0 torn chips, helical chips 0.5 coiled chips with 1 to 2 turns 0.75 coiled chips with an arc that forms an angle of 270 to 360 1 coiled chips with an arc that forms an angle of 180 to 270 1.25 coiled chips with an arc that forms an angle of less than 180

[0068] Chip form number 1 corresponds to the lead-containing reference alloy CuZn39Pb3 (sample No. 16).

[0069] The results of the studies are documented in tables 1 to 4. The unannealed samples No. 1 to No. 15 (table 1) and the annealed samples No. 27 to 34 (table 3) are inventive samples. The unannealed samples No. 16 to No. 26 (table 2) and the annealed samples No. 35 to 45 (table 4) are comparative samples and are identified by (*).

[0070] Machinability of the samples was assessed using the bending moment ascertained in the planing and the shape of the chips. An average bending moment of not more than 36 Nm and chips that correspond to chip form number 1 or 1.25 were considered to be very favorable.

[0071] In addition, an attempt was made to parametrize the measured average bending moment as a function of the proportion by volume of the phase and the proportions by weight of Si, P and Pb. The functional relationship thus ascertained can be presented as follows:

[00002]$f=107.378-2,25255.Math.\left[\mathrm{beta}\right]-64.1438.Math.\left[\mathrm{Si}\right]-115.18.Math.\left[P\right]-30.7071.Math.\left[\mathrm{Pb}\right]+0.017965.Math.\left[\mathrm{beta}\right].Math.\left[\mathrm{beta}\right]+24.6217.Math.\left[\mathrm{Si}\right].Math.\left[\mathrm{Si}\right]+66.7257.Math.\left[P\right].Math.\left[P\right]+0.542512.Math.\left[\mathrm{beta}\right].Math.\left[\mathrm{Si}\right]+1.36208.Math.\left[\mathrm{beta}\right].Math.\left[P\right]+43.4012.Math.\left[\mathrm{Si}\right].Math.\left[P\right]$

where f approximately quantifies the measured bending moment in Nm and where [beta] denotes the proportion of the phase in % by volume, [Si] the proportion of silicon in % by weight, [P] the proportion of phosphorus in % by weight, and [Pb] the proportion of lead in % by weight. The value of f calculated by this formula is documented in the last column of tables 1 to 4. Comparison of this value f with the measured bending moment shows very good agreement between the two parameters. Inventive samples No. 1 to No. 15 and No. 27 to No. 34, all of which have a measured bending moment of less than 36 Nm, are characterized in that the value of f is less than 37.

TABLE-US-00002 Other Phosphides Phosphides Phosphides Cu Zn Si P Pb elements phase phase grain 0.5-1 m 1-2 m 2-5 m Sample % by % by % by % by % by % by % by % by size per per per No. wt. wt. wt. wt. wt. wt. vol. vol. m 21 000 m.sup.2 21 000 m.sup.2 21 000 m.sup.2 1 59.979 39.365 0.269 0.379 63 35 12 128 103 45 2 60.876 38.534 0.286 0.295 76 24 15 385 74 3 3 63.001 36.005 0.68 0.307 72 28 13 181 56 28 4 62.512 36.593 0.591 0.299 78 22 11 92 37 20 5 64.440 34.22 1.013 0.320 80 20 14 153 56 25 6 63.219 35.702 0.676 0.302 0.091 79 21 13 105 33 13 7 62.435 36.553 0.591 0.310 0.102 76 24 15 207 121 31 8 64.496 34.094 0.992 0.298 0.115 80 20 14 319 43 13 9 63.049 35.832 0.704 0.309 Fe: 0.1 78 22 14 75 21 9 B: 0.0025 10 61.508 37.537 0.684 0.266 64 36 9 614 132 12 11 61.078 38.044 0.586 0.288 63 37 14 270 285 15 12 63.055 35.642 0.997 0.302 72 28 12 345 146 16 13 61.489 37.414 0.666 0.330 0.091 74 26 10 424 192 21 14 61.100 37.896 0.581 0.322 0.094 68 32 10 716 99 14 15 63.096 35.484 1.004 0.317 0.095 63 37 11 76 77 20

TABLE-US-00003 TABLE 1 inventive samples, unannealed Other Cu Zn Si P Pb elements Elongation El. Chip form Sample % by % by % by % by % by % by Hardness R.sub.m at break conductivity Torque number f No. wt. wt. wt. wt. wt. wt. HV10 MPa % MS/m Nm 1 59.977 39.363 0.269 0.383 191 565 6.8 12.43 33.6 1.25 28.6 2 60.876 38.534 0.286 0.295 185 564 10.2 12.06 35.7 1 36.2 3 63.001 36.005 0.68 0.307 189 593 10.9 9.54 31.0 1.25 28.2 4 62.512 36.593 0.591 0.299 190 581 10.9 10.02 31.5 1.25 32.4 5 64.440 34.22 1.013 0.320 196 597 9.9 8.37 32.9 1.25 33.6 6 63.219 35.702 0.676 0.302 0.091 195 593 12.6 9.43 29.0 1 29.6 7 62.435 36.553 0.591 0.310 0.102 180 580 10.3 10.03 28.2 1 27.7 8 64.496 34.094 0.992 0.298 0.115 197 601 12.1 8.23 27.4 1 29.9 9 63.049 35.832 0.704 0.309 Fe: 0.1 190 598 11.9 9.46 32.3 1.25 31.4 B: 0.0025 10 61.508 37.537 0.684 0.266 194 602 7.2 10.07 25.6 1.25 25.6 11 61.078 38.044 0.586 0.288 183 584 7.6 10.55 26.1 1 25.5 12 63.055 35.642 0.997 0.302 203 619 9.4 8.6 25.4 1 29.9 13 61.489 37.414 0.666 0.330 0.091 189 598 4.7 9.98 25.2 1 26.2 14 61.100 37.896 0.581 0.322 0.094 192 574 4.8 10.43 24.9 1 23.9 15 63.096 35.484 1.004 0.317 0.095 200 618 7.7 8.57 24.5 1.25 26.3 Other Phosphides Phosphides Phosphides Cu Zn Si P Pb elements phase phase grain 0.5-1 um 1-2 m 2-5 m Sample % by % by % by % by % by % by % by % by size per per per No. wt. wt. wt. wt. wt. wt. vol. vol. m 21 000 m.sup.2 21 000 m.sup.2 21 000 m.sup.2 16 (*) 57.644 39.004 3.348 70 30 17 17 (*) 59.519 40.165 59 41 21 18 (*) 60.854 38.868 0.269 65 35 23 19 (*) 60.774 38.888 0.281 0.051 68 32 19 33 8 20 (*) 60.922 38.69 0.277 0.102 67 33 20 195 79 21 (*) 62.404 37.056 0.53 73 27 25 22 (*) 62.296 37.015 0.579 0.102 71 29 22 94 103 2 23 (*) 59.761 39.993 0.241 75 25 15 18 15 24 (*) 58.791 40.909 0.294 73 27 11 33 27 6 25 (*) 62.910 35.755 0.68 0.648 79 21 14 340 118 79 26 (*) 61.886 36.765 0.697 0.644 79 21 17 266 196 53

TABLE-US-00004 TABLE 2 Comparative samples, unannealed Other Cu Zn Si P Pb elements Elongation El. Chip form Sample % by % by % by % by % by % by Hardness R.sub.m at break conductivity Torque number f No. wt. wt. wt. wt. wt. wt. HV10 MPa % MS/m Nm 16 (*) 57.644 39.004 3.348 22.0 1 17 (*) 59.519 40.165 156 492 22.3 16.78 64.9 0 45.2 18 (*) 60.854 38.868 0.269 173 525 20.4 13.58 35.2 0.5 40.2 19 (*) 60.774 38.888 0.281 0.051 167 540 17 13.12 33.6 0.75 39.6 20 (*) 60.922 38.69 0.277 0.102 167 531 14.6 12.73 35.4 1 36.4 21 (*) 62.404 37.056 0.53 174 538 16.2 11.4 36.5 0.5 40.3 22 (*) 62.296 37.015 0.579 0.102 174 560 10.6 10.7 33.2 1 32.9 23 (*) 59.761 39.993 0.241 163 515 17.9 15.08 49.9 1.25 46.6 24 (*) 58.791 40.909 0.294 174 527 12.1 15.74 39.0 1.25 42.4 25 (*) 62.910 35.755 0.68 0.648 200 593 7.2 9.22 31.5 1.25 34.6 26 (*) 61.886 36.765 0.697 0.644 192 606 4.6 9.42 26.2 1.25 34.6 Other Phosphides Phosphides Phosphides Cu Zn Si P Pb elements phase phase grain 0.5-1 m 1-2 m 2-5 m Sample % by % by % by % by % by % by % by % by size per per per No. wt. wt. wt. wt. wt. wt. vol. vol. m 21 000 m.sup.2 21 000 m.sup.2 21 000 m.sup.2 27 59.977 39.363 0.269 0.383 62 38 15 105 106 44 28 60.876 38.534 0.286 0.295 61 39 21 73 47 45 29 61.508 37.537 0.684 0.266 73 27 11 318 62 15 30 61.078 38.044 0.586 0.288 77 23 12 207 112 21 31 63.055 35.642 0.997 0.302 74 26 16 211 106 28 32 61.489 37.414 0.666 0.33 0.091 69 31 11 238 103 20 33 61.1 37.896 0.581 0.322 0.094 74 26 13 162 96 29 34 63.096 35.484 1.004 0.317 0.095 78 22 14 93 38 17

TABLE-US-00005 TABLE 3 inventive samples, annealed Other Cu Zn Si P Pb elements Elongation El. Chip form Sample % by % by % by % by % by % by Hardness R.sub.m at break conductivity Torque number f No. wt. wt. wt. wt. wt. wt. HV10 MPa % MS/m Nm 27 59.977 39.363 0.269 0.383 173 555 15 12.45 32.3 1.25 27.8 28 60.876 38.534 0.286 0.295 172 526 13.4 12.06 34.0 1 27.7 29 61.508 37.537 0.684 0.266 189 597 10.3 10.81 30.3 1.25 29.1 30 61.078 38.044 0.586 0.288 183 573 10.9 11.19 30.7 1 32.0 31 63.055 35.642 0.997 0.302 194 600 10.5 9.15 28.8 1 30.6 32 61.489 37.414 0.666 0.33 0.091 189 578 5.2 10.64 27.9 1 24.2 33 61.1 37.896 0.581 0.322 0.094 189 574 7.7 11.15 28.0 1 26.7 34 63.096 35.484 1.004 0.317 0.095 194 604 8.1 9.07 27.3 1.25 29.5 Other Phosphides Phosphides Phosphides Cu Zn Si P Pb elements phase phase grain 0.5-1 m 1-2 m 2-5 m Sample % by % by % by % by % by % by % by % by size per per per No. wt. wt. wt. wt. wt. wt. vol. vol. m 21 000 m.sup.2 21 000 m.sup.2 21 000 m.sup.2 35 (*) 60.854 38.868 0.269 70 30 31 36 (*) 60.774 38.888 0.281 0.051 64 36 31 22 15 37 (*) 60.922 38.69 0.277 0.102 69 31 39 23 38 18 38 (*) 62.404 37.056 0.53 69 31 38 39 (*) 62.296 37.015 0.579 0.102 65 35 33 20 27 24 40 (*) 59.761 39.993 0.241 70 30 22 23 32 44 41 (*) 58.791 40.909 0.294 63 37 23 20 25 58 42 (*) 63.001 36.005 0.68 0.307 82 18 15 96 110 66 43 (*) 62.512 36.593 0.591 0.299 81 19 17 167 96 32 44 (*) 64.44 34.22 1.013 0.32 82 18 20 117 99 53 45 (*) 62.91 35.755 0.68 0.648 91 9 17 201 190 66

TABLE-US-00006 TABLE 4 Comparative samples, annealed Other Cu Zn Si P Pb elements Elongation El. Chip form Sample % by % by % by % by % by % by Hardness R.sub.m at break conductivity Torque number f No. wt. wt. wt. wt. wt. wt. HV10 MPa % MS/m Nm 35 (*) 60.854 38.868 0.269 150 489 21.5 13.7 38.6 0 44.9 36 (*) 60.774 38.888 0.281 0.051 161 511 17.7 13.13 35.9 0.75 36.4 37 (*) 60.922 38.69 0.277 0.102 163 515 15.6 12.67 35.1 1 38.1 38 (*) 62.404 37.056 0.53 164 510 20.6 11.51 42.9 0.5 36.6 39 (*) 62.296 37.015 0.579 0.102 156 531 12.7 10.71 32.7 1 29.0 40 (*) 59.761 39.993 0.241 150 475 19.1 14.8 39.7 1 41.9 41 (*) 58.791 40.909 0.294 169 501 17.6 15.6 39.3 1 35.3 42 (*) 63.001 36.005 0.68 0.307 168 540 15.2 10.17 39.3 0.5 34.6 43 (*) 62.512 36.593 0.591 0.299 170 536 15 10.75 39.8 0.5 34.8 44 (*) 64.44 34.22 1.013 0.32 183 557 10.7 8.75 39.4 0.5 34.7 45 (*) 62.91 35.755 0.68 0.648 181 531 8.9 10.21 44.5 1 40.1

[0072] Samples No. 1 to No. 15 (table 1) are inventive samples in the unannealed state. The proportion by volume of the phase is at least 20% and at most 38%. grain size is not more than 15 m. Hardness is at least 180 HV10, and tensile strength R.sub.m at least 560 MPa. Elongation at break is at least 4.7%. The measured bending moment is not more than 35.7 Nm. The form of the chips for all samples corresponds to chip form number 1 or 1.25.

[0073] Samples No. 16 to No. 26 (table 2) are comparative samples in the unannealed state. The reference sample No. 16 contains 3.3% by weight of lead and shows very good machining properties. Sample No. 17 shows that machining properties are very poor without lead and without further alloy elements.

[0074] Sample No. 18, aside from Cu and Zn, contains only 0.27% by weight of Si. The bending moment is good, but the chip form is poor, which can be attributed to the absence of phosphide particles as chip breakers. The same finding is made for sample No. 21, containing 0.53% by weight of Si. Samples No. 19, 20 and 22 have 0.05% to 0.1% by weight of phosphorus, which has a favourable effect on chip form and, at least in the case of sample No. 19 and in the case of sample No. 22, on bending moment as well. In the case of samples No. 19 and 20, however, hardness and tensile strength R.sub.m are well below the values for samples No. 1 to No. 15. Sample No. 22 having an Si content of 0.58% by weight shows only slightly improved hardness and tensile strength. In addition, samples No. 18 to No. 22 show a much greater grain size at 19 to 25 m than samples No. 1 to No. 15. The coarser grain leads to drawbacks in terms of straightness and trueness to scale.

[0075] The silicon-free samples No. 23 and No. 24, with a P content of 0.24% and 0.29% by weight, give an excellent chip form, but the bending moment is at a high level. Samples No. 25 and No. 26, each with a P content of 0.65% by weight, show excellent machining properties. Because of the high P content, however, they have a tendency to crack in the course of hot forming. Furthermore, this results in low elongation at break at room temperature. The high P content is reflected in a large number of phosphide particles having an equivalent diameter of 2 to 5 m. It is thus a sign of poor hot formability and additionally of brittle material characteristics at room temperature if the alloy, in an area of 21 000 m.sup.2, has more than 45 phosphide particles having an equivalent diameter of 2 to 5 m.

[0076] The samples document that silicon leads to a reduction in the bending moment and that phosphorus promotes chip breaking. The combination of the two elements leads overall to good machining properties and to a small grain size.

[0077] Samples No. 27 to No. 34 (table 3) are inventive samples in the annealed state. The proportion by volume of the B phase is at least 22% and at most 39%. In the case of sample No. 28, grain size is 21 m. This can be attributed to the annealing temperature of 600 C. In the case of the other samples that were annealed at 550 C., grain size is not more than 16 m. Compared to samples No. 1 to No. 15, samples No. 27 to No. 34 have a somewhat lower hardness of at least 170 HV10 and a somewhat lower tensile strength R.sub.m of at least 520 HV10. By contrast, annealing improved elongation at break. Consequently, a more ductile material state can be established. Bending moment and chip form are very good to excellent.

[0078] Samples No. 35 to No. 45 (table 4) are comparative samples in the annealed state. The silicon-containing but phosphorus-free samples No. 35 and No. 38 are characterized by an unfavorably high bending moment and poor chip form. Samples No. 36, 37 and 39 having a small P content have a distinct improvement in machine properties compared to samples No. 19, 20 and 22, but hardness and tensile strength are unsatisfactory. In addition, samples No. 25 to No. 39 show a much greater grain size at 31 to 39 m than samples No. 1 to No. 15. The coarser grain leads to drawbacks in terms of straightness and trueness to scale.

[0079] The phosphorus-containing but silicon-free samples No. 40 and 41 give a very good chip form, but bending moment is an unfavorably high-level. The annealed samples No. 42, 43 and 44, which correspond to the unannealed samples No. 3, 4 and 5 in terms of composition, show a higher bending moment and poorer chip form than the unannealed variants. The annealing reduced the proportion by volume of the phase to values below 20% and shifted the distribution of the phosphide particles toward coarser particles. These two effects together lead to a deterioration in machining properties. Sample No. 45 having a P content of 0.65% by weight is characterized by a high bending moment. This is caused by a very small proportion of phase of only 9% by volume. Moreover, the sample has a very high density of phosphides having an equivalent diameter of 2 to 5 m.

[0080] Alloys having an above-described composition can also be used as casting alloys for castings.