Low modulus corrosion-resistant alloy and article comprising the same

Abstract

A low modulus corrosion-resistant alloy is disclosed, and comprises five principal elements, wherein the five principal elements are Zr, Nb, Ti, Mo, and Sn. Experimental data reveal that, samples of the low modulus corrosion-resistant alloy all include following characteristics: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V. As a result, experimental data have proved that this low modulus corrosion-resistant alloy has a significant potential for application in the manufacture of biomedical articles including medical devices and surgical implants. In addition, this low modulus corrosion-resistant alloy is also suitable for application in the manufacture of various industrially-producible articles, including springs, coils, wires, clamps, fasteners, blades, valves, elastic sheets, spectacle frames, sports equipment, and other high-strength low-modulus corrosion-resistant structural materials.

Claims

1. A low modulus corrosion-resistant alloy, having a plurality of properties that comprises: hardness of at least 250 HV, Young's modulus in a range between 70 GPa and 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V, and comprising: at least 40 weight percent Zr, 18.1 to 50 weight percent Nb, 13 to 40 weight percent Ti, 4 to 10 weight percent Mo, and 1.5 to 15 weight percent Sn; wherein a summation of Zr and Ti in weight percent is less than or equal to 80.

2. The low modulus corrosion-resistant alloy of claim 1, wherein the principal crystal structure of the low modulus corrosion-resistant alloy which is processed to be an as-cast state, an as-rolled state, or an as-annealed state all being body-centered cubic (BCC) structure.

3. The low modulus corrosion-resistant alloy of claim 1, further comprising at most 5 weight percent M, wherein M comprises at least one additive element selected from a group consisting of Hf, Ta, Pt, Ag, Au, Al, V, Ni, Cu, Co, C, and O.

4. The low modulus corrosion-resistant alloy of claim 1, being produced by using a manufacturing method selected from a group consisting of: vacuum arc melting method, electric resistance wire heating method, electric induction heating method, rapidly solidification method, mechanical alloying method, and powder metallurgic method.

5. The low modulus corrosion-resistant alloy of claim 1, wherein the low modulus corrosion-resistant alloy is processed to be an article selected from a group consisting of powder article, wire article, rod article, plate article, bulk article, and welding rod.

6. An article, being made of an alloy material, wherein the alloy material has a plurality of properties that comprises: hardness of at least 250 HV, Young's modulus in a range between 70 GPa and 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V, and comprising: at least 40 weight percent Zr, 18.1 to 50 weight percent Nb, 13 to 40 weight percent Ti, 4 to 10 weight percent Mo, and 1.5 to 15 weight percent Sn; wherein a summation of Zr and Ti in weight percent is less than or equal to 80; wherein the article is selected from a group consisting of surgical implant, medical device and industrially-producible product; and wherein the forgoing industrially-producible product is selected from a group consisting of spring, coil, wire, clamp, fastener, blade, valve, elastic sheet, spectacle frame, and sports equipment.

7. A low modulus corrosion-resistant alloy, having a plurality of properties that comprises: hardness of at least 250 HV, Young's modulus in a range between 70 GPa and 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V, and comprising: at least 40 weight percent Zr, 18.1 to 50 weight percent Nb, 13 to 40 weight percent Ti, 4 to 10 weight percent Mo, 1.5 to 15 weight percent Sn, and at most 5 weight percent Fe; wherein a summation of Zr and Ti in weight percent is less than or equal to 80.

8. The low modulus corrosion-resistant alloy of claim 7, wherein the principal crystal structure of the low modulus corrosion-resistant alloy which is processed to be an as-cast state, an as-rolled state, or an as-annealed state all being body-centered cubic (BCC) structure.

9. The low modulus corrosion-resistant alloy of claim 7, further comprising at most 5 weight percent M, wherein M comprises at least one additive element selected from a group consisting of Hf, Ta, Pt, Ag, Au, Al, V, Ni, Cu, Co, C, and O.

10. The low modulus corrosion-resistant alloy of claim 7, being produced by using a manufacturing method selected from a group consisting of: vacuum arc melting method, electric resistance wire heating method, electric induction heating method, rapidly solidification method, mechanical alloying method, and powder metallurgic method.

11. The low modulus corrosion-resistant alloy of claim 7, wherein the low modulus corrosion-resistant alloy is processed to be an article selected from a group consisting of powder article, wire article, rod article, plate article, bulk article, and welding rod.

12. An article, being made of an alloy material, wherein the alloy material has a plurality of properties that comprises: hardness of at least 250 HV, Young's modulus in a range between 70 GPa and 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V, and comprising: at least 40 weight percent Zr, 18.1 to 50 weight percent Nb, 13 to 40 weight percent Ti, 4 to 10 weight percent Mo, 1.5 to 15 weight percent Sn, and at most 5 weight percent Fe; wherein a summation of Zr and Ti in weight percent is less than or equal to 80; wherein the article is selected from a group consisting of surgical implant, medical device and industrially-producible product; and wherein the forgoing industrially-producible product is selected from a group consisting of spring, coil, wire, clamp, fastener, blade, valve, elastic sheet, spectacle frame, and sports equipment.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(1) To more clearly describe a low modulus corrosion-resistant alloy and an article comprising the same, embodiments of the present invention will be described in detail with reference to the attached data hereinafter.

(2) The present invention using three elements with good biocompatibility and two elements with medium biocompatibility to form a low modulus corrosion-resistant alloy. In which, the forgoing three elements with good biocompatibility are Zr, Nb and Ti, and the forgoing two elements with medium biocompatibility are Mo and Sn. As described in more detail below, the low modulus corrosion-resistant alloy comprising: greater than or equal to 31 wt % Zr, from 18 to 50 wt % Nb, from 10 to 40 wt % Ti, from 4 to 10 wt % Mo, and from 1.5 to 15 wt % Sn, and a summation of numeric values of Zr and Ti in weight percent is less than or equal to 80. In the practicable embodiment, the principal crystal structure of the low modulus corrosion-resistant alloy all being body-centered cubic (BCC) structure. According to measurement data, the low modulus corrosion-resistant alloy has a plurality of specific properties, comprising: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V.

First Embodiment

(3) In first embodiment, the low modulus corrosion-resistant alloy is designed to have an elemental composition of xZr-yNb-zTi-aMo-bSn, so as to exhibit a plurality of specific properties that comprises: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V. As described in more detail below, the forgoing x, y, z, a, and b are numeric values of Zr, Nb, Ti, Mo, and Sn in weight percent, respectively. Moreover, x, y, z, a, and b satisfy x≥31, 18≤y≤50, 10≤z≤40, 4≤a≤10, 4≤a≤10, 1.5≤b≤15, and x+z≤80. For example, the low modulus corrosion-resistant alloy is designed to comprises: 31 wt % Zr, 45.8 wt % Nb, 16.3 wt % Ti, 4.9 wt % Mo, and 2 wt % Sn. In such case, the low modulus corrosion-resistant alloy has an elemental composition of 31Zr-45.8Nb-16.3Ti-4.9Mo-2Sn. That is, x=31, y=45.8, z=16.3, a=4.9, and b=2.

Second Embodiment

(4) In second embodiment, the low modulus corrosion-resistant alloy is designed to have an elemental composition of xZr-yNb-zTi-aMo-bSn-sM, thereby showing a plurality of specific properties comprising: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V. As explained in more detail below, M means at least one additive element selected from a group consisting of Hf, Ta, Pt, Ag, Au, Al, V, Ni, Cu, Co, C, and O. On the other hand, the forgoing x, y, z, a, b, and s are numeric values of Zr, Nb, Ti, Mo, Sn, and M in weight percent, respectively. Moreover, x, y, z, a, b, and s satisfy x≥31, 18≤y≤50, 10≤z≤40, 4≤a≤10, 1.5≤b≤15, and x+z≤80. For example, the low modulus corrosion-resistant alloy is designed to comprises: 45.7 wt % Zr, 18.4 wt % Nb, 19.5 wt % Ti, 4.3 wt % Mo, 7.1 wt % Sn, 2 wt % Al, and 1 wt % V. In such case, the low modulus corrosion-resistant alloy has an elemental composition of 45.7Zr-18.4Nb-19.5Ti-4.3Mo-7.1Sn-2Al-1V-1Ni-1Pt. That is, x=45.7, y=18.4, z=19.5, a=4.3, b=7.1, and s=5.

Third Embodiment

(5) In third embodiment, the low modulus corrosion-resistant alloy is designed to have an elemental composition of xZr-yNb-zTi-aMo-bSn-cFe, so as to exhibit a plurality of specific properties that comprises: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V. As described in more detail below, the forgoing x, y, z, a, b, and c are numeric values of Zr, Nb, Ti, Mo, Sn, and Fe in weight percent, respectively. Moreover, x, y, z, a, b, and c satisfy x≥31, 18≤y≤50, 10≤z≤40, 4≤a≤10, 1.5≤b≤15, and x+z≤80. For example, the low modulus corrosion-resistant alloy is designed to comprises: 53 wt % Zr, 21.6 wt % Nb, 15.9 wt % Ti, 4.8 wt % Mo, 4 wt % Sn, and 0.7 wt % Fe. In such case, the low modulus corrosion-resistant alloy has an elemental composition of 53Zr-21.6Nb-15.9Ti-4.8Mo-4Sn-0.7Fe. That is, x=53, y=21.6, z=15.9, a=4.8, b=4, and c=0.7.

Fourth Embodiment

(6) In fourth embodiment, the low modulus corrosion-resistant alloy is designed to have an elemental composition of xZr-yNb-zTi-aMo-bSn-cFe-sM, thereby showing a plurality of specific properties comprising: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V. As explained in more detail below, M means at least one additive element selected from a group consisting of Hf, Ta, Pt, Ag, Au, Al, V, Ni, Cu, Co, C, and O. On the other hand, the forgoing x, y, z, a, b, c, and s are numeric values of Zr, Nb, Ti, Mo, Sn, Fe, and M in weight percent, respectively. Moreover, x, y, z, a, b, c, and s satisfy x≥31, 18≤y≤50, 10≤z≤40, 4≤a≤10, 1.5≤b≤15, c≤5, s≤5, and x+z≤80. For example, the low modulus corrosion-resistant alloy is designed to comprises: 52 wt % Zr, 20.6 wt % Nb, 15.9 wt % Ti, 4.8 wt % Mo, 4 wt % Sn, 0.7 wt % Fe, 1 wt % Co, and 1 wt % Ta. In such case, the low modulus corrosion-resistant alloy has an elemental composition of 52Zr-20.6Nb-15.9Ti-4.8Mo-4Sn-0.7Fe-1Co-1Ta. That is, x=52, y=20.6, z=15.9, a=4.8, b=4, c=0.7, and s=2.

(7) It is worth mentioning that, the low modulus corrosion-resistant alloy according to the present invention can be produced by using a manufacturing method selected from a group consisting of: vacuum arc melting method, electric resistance wire heating method, electric induction heating method, rapidly solidification method, mechanical alloying method, and powder metallurgic method. Moreover, the low modulus corrosion-resistant alloy can be processed to be an as-cast state, an as-rolled state or an as-annealed state in a practicable application, so as to be made to an article selected from a group consisting of powder article, wire article, rod article, plate article, bulk article, and welding rod.

(8) Therefore, engineers skilled in the development and manufacture of alloys are certainly able to fabricate a specific article comprising the low modulus corrosion-resistant alloy according to the present invention, such as a surgical implant, a medical device, or an industrially-producible product. In practicable embodiments, the surgical implant can be an artificial hip joint, an artificial knee joint, a joint button, a bone plate, a bone screw, a spicule, a dental crown, an abutment post for supporting the dental crown, a bridge, a partial denture, etc. On the other hand, the medical device can be a scalpel's blade, a hemostatic forceps, a surgical scissor, an electric bone drill, a tweezer, a blood vessel suture needle, a sternum suture thread, and so on. Moreover, the industrially-producible product is like spring, coil, wire, clamp, fastener, blade, valve, elastic sheet, spectacle frame, sports equipment, and other high-strength low-modulus corrosion-resistant structural materials. As explained in more detail below, process way for achieving the fabrication of the specific article can be casting method, electric-arc welding method, thermal spraying method, thermal sintering method, laser welding method, plasma-arc welding method, 3D additive manufacturing method, mechanical process method, or chemical process method.

(9) It is worth mentioning that, the inventor of the present invention has completed experiments in order to prove that the low modulus corrosion-resistant alloy according to the present invention can indeed be made.

First Experiment Example

(10) In the first experiment example, samples of the low modulus corrosion-resistant alloy according to the present invention are fabricated by using the vacuum arc melting method. Following Table (1) lists each sample's elemental composition. Moreover, tensile test, hardness measurement, microstructure analysis, and potentiodynamic polarization test for the samples of the low modulus corrosion-resistant alloy are also completed, and related measurement data are recorded in the following Table (2).

(11) TABLE-US-00001 TABLE 1 Samples Elemental composition No. 1 31Zr—45.8Nb—16.3Ti—4.9Mo—2Sn No. 2 31Zr—45.8Nb—15.3Ti—4.9Mo—1.5Sn—1.5Fe No. 3 35.7Zr—41.1Nb—16.3Ti—4.9Mo—2Sn No. 4 35.7Zr—41.1Nb—14.3Ti—4.9Mo—1.5Sn—2.5Fe No. 5 40.4Zr—36.4Nb—16.3Ti—4.9Mo—2Sn No. 6 40.4Zr—36.4Nb—13.3Ti—4.9Mo—1.5Sn—3.5Fe No. 7 45.1Zr—31.7Nb—16.3Ti—4.9Mo—2Sn No. 8 45.1Zr—31.7Nb—13.3Ti—4.9Mo—1.5Sn—3.5Fe No. 9 54.5Zr—22.2Nb—16.3Ti—5Mo—2Sn No. 10 54.5Zr—22.2Nb—12.8Ti—5Mo—1.5Sn—4Fe No. 11 52Zr—21.1Nb—15.6Ti—9.4Mo—1.9Sn No. 12 52Zr—21.1Nb—15.1Ti—9.4Mo—1.9Sn—0.5Fe

(12) TABLE-US-00002 TABLE 2 Young's Yield Critical pitting Hardness modulus strength potential Samples (HV) (GPa) (MPa) (V) No. 1 312 93.3 1040 >1.3 No. 2 341 98.1 1124 >1.3 No. 3 311 90.2 1035 >1.3 No. 4 345 97.8 1132 >1.3 No. 5 302 88.5 1006 >1.3 No. 6 344 94.3 1084 >1.3 No. 7 289 83.6 970 >1.3 No. 8 322 90.2 1036 >1.3 No. 9 282 77.8 946 >1.3 No. 10 312 86.5 998 >1.3 No. 11 331 94.3 1096 >1.3 No. 12 342 97.4 1136 >1.3

(13) From the forgoing Table (2), it is easy to find that, 12 samples of the low modulus corrosion-resistant alloy all include following characteristics: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V.

Second Experiment Example

(14) In the second experiment example, samples of the low modulus corrosion-resistant alloy according to the present invention are fabricated by also using the vacuum arc melting method. Following Table (3) lists each sample's elemental composition. Moreover, tensile test, hardness measurement, microstructure analysis, and potentiodynamic polarization test for the samples of the low modulus corrosion-resistant alloy are also completed, and related measurement data are recorded in the following Table (4).

(15) TABLE-US-00003 TABLE 3 Samples Elemental composition No. 13 53.4Zr—21.8Nb—16Ti—4.8Mo—4Sn No. 14 51.4Zr—20.8Nb—15Ti—4.8Mo—4Sn—2Al—2Ta No. 15 51.4Zr—20.8Nb—14Ti—4.8Mo—4Sn—2V—1Ni—1Cu—1Pt No. 16 51.4Zr—20.9Nb—15.5Ti—4.6Mo—7.6Sn No. 17 49.4Zr—19.9Nb—14.5Ti—4.6Mo—7.6Sn—3Co—1Ag No. 18 49.4Zr—19.9Nb—14.5Ti—4.6Mo—7.6Sn—1Al—1V—1Ni—1Au No. 19 49.5Zr—20.2Nb—14.8Ti—4.5Mo—11Sn No. 20 47.5Zr—19.2Nb—14.8Ti—4.5Mo—11Sn—3Cu No. 21 47.5Zr—19.2Nb—12.8Ti—4.5Mo—11Sn—2Co—1C—1O—1Pt No. 22 47.7Zr—19.5Nb—14.3Ti—4.3Mo—14.2Sn No. 23 53Zr—21.6Nb—15.9Ti—4.8Mo—4Sn—0.7Fe No. 24 52Zr—20.6Nb—15.9Ti—4.8Mo—4Sn—0.7Fe—1Co—1Ta No. 25 51Zr—20.6Nb—13.9Ti—4.8Mo—4Sn—0.7Fe—2C—1O—1Al—1Pt No. 26 52.7Zr—21.5Nb—15.8Ti—4.7Mo—3.9Sn—1.4Fe No. 27 50.7Zr—20.5Nb—14.8Ti—4.7Mo—3.9Sn—1.4Fe—2V—2Ag No. 28 50.7Zr—20.5Nb—14.3Ti—4.7Mo—3.9Sn—1.4Fe—2Ni—1Cu—1Co—0.5Au No. 29 47.7Zr—19.4Nb—21.5Ti—4.3Mo—7.1Sn No. 30 46.7Zr—18.4Nb—19.5Ti—4.3Mo—7.1Sn—2C—2Ta No. 31 45.7Zr—18.4Nb—19.5Ti—4.3Mo—7.1Sn—2Al—1V—1Ni—1Pt No. 32 44.6Zr—18.1Nb—26.7Ti—4Mo—6.6Sn No. 33 42.6Zr—18.1Nb—24.7Ti—4Mo—6.6Sn—3Cu—1Ag No. 34 42.6Zr—18.1Nb—23.7Ti—4Mo—6.6Sn—2Co—1Ni—1C—0.5O—0.5Au

(16) TABLE-US-00004 TABLE 4 Young's Yield Critical pitting Hardness modulus strength potential Samples (HV) (GPa) (MPa) (V) No. 13 286 79.9 961 >1.3 No. 14 318 85.1 1009 >1.3 No. 15 353 92.3 1123 >1.3 No. 16 318 88.2 1055 >1.3 No. 17 347 95.8 1116 >1.3 No. 18 356 97.2 1173 >1.3 No. 19 348 95.7 1104 >1.3 No. 20 368 98.9 1217 >1.3 No. 21 402 99.7 1230 >1.3 No. 22 391 99.8 1179 >1.3 No. 23 306 82.8 1021 >1.3 No. 24 323 87.3 1057 >1.3 No. 25 367 97.8 1163 >1.3 No. 26 337 91.3 1111 >1.3 No. 27 364 99.4 1159 >1.3 No. 28 367 98.7 1161 >1.3 No. 29 303 81.2 991 >1.3 No. 30 358 90.4 1072 >1.3 No. 31 372 95.6 1112 >1.3 No. 32 300 77.5 990 >1.3 No. 33 334 82.8 1032 >1.3 No. 34 388 97.5 1174 >1.3

(17) From the forgoing Table (4), it is easy to find that, 22 samples of the low modulus corrosion-resistant alloy all include following characteristics: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V.

Third Experiment Example

(18) In the third experiment example, samples No. 13 and No. 32 of the low modulus corrosion-resistant alloy of the present invention, a conventional type 316L stainless steel, a conventional Co-28Cr-6Mo alloy, and a conventional Ti-6Al-4V alloy are taken for further completing multi tests, and related measurement data are recorded in the following Table (5).

(19) TABLE-US-00005 TABLE 5 type 316L Test stainless CoCrMo Ti—6Al—4V Sample Sample items steel alloy alloy No. 13 No. 32 Density 8.00 8.25 4.42 6.53 6.13 (g/cm.sup.3) Price 0.15 0.86 0.78 1.42 1.24 (TWD/g) Hardness 155 300 348.7 286.0 300.0 (HV) Yield 190 450 795 961 990 strength (MPa) Young's 193 220 116 79.9 77.5 modulus (GPa) Corrosion 3.2 × 6.4 × 2.1 × 1.6 × 1.9 × current 10.sup.−7 10.sup.−8 10.sup.−8 10.sup.−8 10.sup.−8 (A/cm.sup.2) Critical 0.812 0.535 >1.3 >1.3 >1.3 pitting potential (V)

(20) From the forgoing Table (5), it is easy to find that, samples No. 13 and No. 32 of the low modulus corrosion-resistant alloy both include characteristics of hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V. Therefore, experimental data have proved that, the low modulus corrosion-resistant alloy of the present invention exhibits outstanding mechanical property and corrosion resistance superior to that of the conventional type 316L stainless steel, Co-28Cr-6Mo alloy, and Ti-6Al-4V alloy.

(21) Therefore, through the above descriptions, all embodiments and their experimental data of the low modulus corrosion-resistant alloy according to the present invention have been introduced completely and clearly; in summary, the present invention includes the advantages of:

(22) (1) The present invention discloses a low modulus corrosion-resistant alloy comprising five principal elements, wherein the five principal elements are Zr, Nb, Ti, Mo, and Sn. According to the present invention, the low modulus corrosion-resistant alloy consists of Zr more than 31 wt %, 18-50 wt % Nb, 10-40 wt % Ti, 4-10 wt % Mo, and 1.5-15 wt % Sn, wherein a summation of Zr and Ti in weight percent is less than or equal to 80. It is worth mentioning that, experimental data have revealed that, samples of the low modulus corrosion-resistant alloy all include following characteristics: hardness of at least 250 HV, Young's modulus less than 100 GPa, yield strength greater than 600 MPa, and critical pitting potential greater than 1.3V.

(23) (2) According to the experimental data, it is believed that the low modulus corrosion-resistant alloy of the present invention has a significant potential for application in the manufacture of biomedical articles including medical devices and surgical implants. In addition, this low modulus corrosion-resistant alloy is also suitable for application in the manufacture of various industrially-producible articles, including springs, coils, wires, clamps, fasteners, blades, valves, elastic sheets, spectacle frames, sports equipment, and other high-strength low-modulus corrosion-resistant structural materials.

(24) The above description is made on embodiments of the present invention. However, the embodiments are not intended to limit the scope of the present invention, and all equivalent implementations or alterations within the spirit of the present invention still fall within the scope of the present invention.