A Pt-based superalloy material for spark plugs and its preparation method

Abstract

The present invention discloses a Pt-based superalloy material for spark plugs and a preparation method thereof, including: the addition amounts of Y and Sc by weight percentage are respectively 0.01% to 0.15%, the addition amount of Ru is 5 to 15%, and the balance is Pt, wherein: the total addition amount of the two elements Y and Sc is not higher than 0.15%. In order to further improve the performance of the Pt-based alloy for spark plugs, control the alloy cost, and improve the convenience of the alloy preparation process, the present invention starts from the alloy composition design, strengthens the alloy by adding Y and Sc elements simultaneously, and ensures the high melting point of the alloy while reducing the alloy cost by adding Ru element. The alloy performance is further improved by ordered heat treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of spark plug electrodes, and in particular to a Pt-based superalloy material for spark plugs and a preparation method thereof. Background Art

[0002] The element Pt has a high melting point and stable chemical properties, and is an ideal high-temperature material and a superalloy material widely used in the field of spark plugs. However, Pt has low high-temperature strength and low resistance to weld spatter. Usually, elements such as Ir, Rh, Ni, and Ru are added to strengthen the alloy so as to improve the comprehensive high-temperature performance of the alloy. In general application scenarios, Ir and Rh have better strengthening effects, but the cost of the alloy material is relatively high and it has not been widely used.

[0003] Document 1, CN104674048A reports a Pt-Ru-based superalloy material and a preparation method thereof: the main elements of the alloy are Pt and Ru. By adding one or more of Re, Al, W, Ta, Nb, Ti, Zr, Cr, and Ni, and then adding one or more of rare earth elements La, Nd, Pr, Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ce, and Th, a quaternary, quinary, or hexary alloy is finally prepared.

[0004] Document 2, CN114107723A reports a crucible for drawing glass fibers, a Pt-based superalloy, and a preparation method thereof: the content of Ru in the Pt-based superalloy is 0.5 wt% - 20 wt%, and it also contains element Me, where element Me is at least one of Cr, Nd, Sm, Sc, Er, Dy, and Ta, and the content is 0.05 wt% - 1.5 wt%. A dense oxide film is formed on the surface of the alloy of this invention.

[0005] The alloy in Document 1 has many alloying elements, which brings difficulties to the uniformity of alloying elements during the alloy preparation process. The dense oxide film formed on the surface of the alloy in Document 2 affects the electrical conductivity and is not suitable for use as a spark plug electrode material. Summary of the Invention

[0006] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] In view of the problems existing in the above-mentioned existing Pt-based superalloy materials for spark plugs and their preparation methods, the present invention is proposed.

[0008] Therefore, the object of the present invention is to provide a Pt-based superalloy material for spark plugs and a preparation method thereof. Starting from the alloy composition design, the alloy is strengthened by adding Y and Sc elements simultaneously, the high melting point of the alloy is ensured by adding Ru element while reducing the alloy cost, and then the alloy performance is further improved by ordered heat treatment.

[0009] To solve the above technical problems, the present invention provides the following technical solutions: A Pt-based superalloy material for spark plugs, comprising:

[0010] The addition amounts of Y and Sc by weight percentage are 0.01% - 0.15% respectively, the addition amount of Ru is 5 - 15%, and the balance is Pt.

[0011] As a preferred embodiment of the Pt-based superalloy material for spark plugs of the present invention, among them: the total addition amount of the two elements Y and Sc is not higher than 0.15%.

[0012] A preparation method of a Pt-based superalloy material for spark plugs, comprising the following steps:

[0013] Step 1: The addition amounts of Y and Sc by weight percentage are 0.01% - 0.15% respectively, the total addition amount of the two elements is not higher than 0.15%, the addition amount of Ru is 5 - 15%, and the balance is Pt;

[0014] Step 2: Put the elements Y, Sc, Ru, and Pt into a crucible, and carry out vacuum high-frequency melting. After melting, pour it into a water-cooled copper mold to obtain an ingot;

[0015] Step 3: The ingot is subjected to homogenization heat treatment at 1250°C for 4 hours;

[0016] Step 4: The ingot is hot forged at 1250°C to obtain a bar with a diameter of 6 mm;

[0017] Step 5: The bar obtained in Step 4 is rolled on a pass mill with a semi-circular pass to obtain a wire with a diameter of 2 mm. When the total deformation reaches 45%, annealing is carried out at 1250°C for 45 minutes, and after annealing, water quenching in ice-salt water is carried out;

[0018] Step 6: The wire obtained in Step 5 is drawn on a multi-mode wire drawing machine to the finished size of 0.3 - 0.5 mm; the pass deformation amount does not exceed 8%. When the total deformation reaches 45%, annealing is carried out at 1200°C for 30 minutes, and after annealing, water quenching in ice-salt water is carried out;

[0019] Step 7: Ordered heat treatment, the hard wire drawn to the finished size is subjected to ordered heat treatment at 750 - 780°C for 30 minutes.

[0020] As a preferred embodiment of the preparation method of the Pt-based superalloy material for spark plugs according to the present invention, wherein: the crucible is a high-purity zirconia crucible or cold crucible levitation melting is adopted.

[0021] As a preferred embodiment of the preparation method of the Pt-based superalloy material for spark plugs according to the present invention, wherein: in step four, slow hot forging is adopted for hot forging.

[0022] As a preferred embodiment of the preparation method of the Pt-based superalloy material for spark plugs according to the present invention, wherein: the rolling deformation amount of each pass of the obtained 2-mm wire in step five does not exceed 12%.

[0023] Advantages of the present invention: The Pt-based superalloy material for spark plugs of the present invention has good comprehensive performance, low cost, and convenient production and processing. To further improve the performance of the Pt-based alloy for spark plugs, while controlling the alloy cost and improving the convenience of the alloy preparation process, the present invention starts from the alloy composition design, strengthens the alloy by adding Y and Sc elements simultaneously, and reduces the alloy cost while ensuring the high melting point of the alloy by adding Ru element. The alloy performance is further improved by ordered heat treatment. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0025] Figure 1 It is a diagram showing the influence of Example 14 and Comparative Example 2 on the hardness of the Pt-based superalloy material for spark plugs and its preparation method of the present invention.

[0026] Figure 2 It is a metallographic structure diagram of Example 14 of the Pt-based superalloy material for spark plugs and its preparation method of the present invention at 1250 °C and annealed for 45 minutes. Detailed Embodiments

[0027] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the detailed embodiments of the present invention will be described in detail below with reference to the drawings of the specification.

[0028] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0030] Reference Figure 1 -2. A method for preparing a Pt-based high-temperature alloy material for a spark plug, comprising the following steps:

[0031] Step 1, Y and Sc are added in amounts of 0.01% to 0.15% by weight respectively, the total amount of the two elements added is not higher than 0.15%, Ru is added in an amount of 5-15%, and the balance is Pt;

[0032] Step 2: Y, Sc, Ru, and Pt elements are placed in a crucible, and smelted in a vacuum high frequency furnace. After smelting, the elements are poured into a water-cooled copper mold to obtain an ingot;

[0033] Step 3: homogenizing the ingot at 1250°C for 4 hours;

[0034] Step 4: hot forging the ingot at 1250°C to obtain a 6mm diameter bar;

[0035] Step 5: The rod obtained in step 4 is rolled on a semicircular pass rolling mill to obtain a wire with a diameter of 2 mm. When the total deformation reaches 45%, annealing is performed at 1250° C. for 45 minutes, and quenching is performed in ice salt water after annealing.

[0036] Step 6: The wire obtained in step 5 is drawn on a multi-mode wire drawing machine to a finished product size of 0.3-0.5 mm; when the deformation per pass does not exceed 8% and the total deformation reaches 45%, annealing is performed at 1200°C for 30 minutes, and quenching is performed in ice salt water after annealing;

[0037] Step 7: Orderly heat treatment: The hard wire drawn to the finished size is subjected to orderly heat treatment at 750-780°C for 30 minutes.

[0038] Specific embodiments and comparative examples are as follows:

[0039] Example 1

[0040] Step 1: Prepare the ingredients by weight percentage: Y: 0.14%, Sc: 0.01%, Ru: 5%, Pt balance;

[0041] Step 2: Vacuum melting and casting in a water-cooled copper mold to obtain an ingot with a diameter of 17 mm;

[0042] Step 3: The ingot is subjected to homogenization heat treatment at 1250°C for 4 hours;

[0043] Step 4: The ingot is hot forged at 1250°C to obtain a 6mm diameter bar;

[0044] Step 5: The bar is rolled on a semicircular pass mill to obtain a wire with a diameter of 2 mm. The deformation of each rolling process does not exceed 12%. When the total deformation reaches 45%, annealing is performed at 1250°C for 45 minutes. After annealing, quenching is performed in ice salt water.

[0045] Step 6: The wire is drawn on a multi-mode wire drawing machine to a finished size of 0.3-0.5 mm. When the deformation per pass does not exceed 8% and the total deformation reaches 45%, annealing is performed at 1200°C for 30 minutes, and quenching is performed in ice salt water after annealing.

[0046] Step 7: Orderly heat treatment: the hard wire pulled to the finished size is subjected to ordering heat treatment at 750℃ for 30 minutes.

[0047] Example 2

[0048] Step 1: Prepare the ingredients by weight percentage: Y: 0.09%, Sc: 0.01%, Ru: 5%, Pt balance;

[0049] The remaining steps are the same as in Example 1.

[0050] Example 3

[0051] Step 1: Prepare the ingredients by weight percentage: Y: 0.01%, Sc: 0.01%, Ru: 5%, Pt balance;

[0052] The remaining steps are the same as in Example 1.

[0053] Example 4

[0054] Step 1: Prepare the ingredients by weight percentage: Y: 0.01%, Sc: 0.14%, Ru: 5%, Pt balance;

[0055] The remaining steps are the same as in Example 1.

[0056] Example 5

[0057] Step 1: Mix the ingredients by weight percentage: Y: 0.01%, Sc: 0.09%, Ru: 5%, Pt balance;

[0058] The remaining steps are the same as in Example 1.

[0059] Example 6

[0060] Step 1: Prepare the ingredients by weight percentage: Y: 0.01%, Sc: 0.14%, Ru: 8%, Pt balance;

[0061] The remaining steps are the same as in Example 1.

[0062] Example 7

[0063] Step 1: Prepare the ingredients by weight percentage: Y: 0.14%, Sc: 0.01%, Ru: 8%, Pt balance;

[0064] The remaining steps are the same as in Example 1.

[0065] Example 8

[0066] Step 1: Mix the ingredients by weight percentage: Y: 0.05%, Sc: 0.07%, Ru: 8%, and Pt as the balance;

[0067] The remaining steps are the same as in Example 1.

[0068] Example 9

[0069] Step 1: Prepare the ingredients by weight percentage: Y: 0.01%, Sc: 0.14%, Ru: 12%, Pt balance;

[0070] Steps 2 to 6 are the same as in Example 1;

[0071] Step 7: Orderly heat treatment: the hard wire pulled into finished size is subjected to orderly heat treatment at 780°C for 30 minutes.

[0072] Example 10

[0073] Step 1: Prepare the ingredients by weight percentage: Y: 0.14%, Sc: 0.01%, Ru: 12%, Pt balance;

[0074] The remaining steps are the same as in Example 9.

[0075] Embodiment 11

[0076] Step 1: Prepare the ingredients by weight percentage: Y: 0.07%, Sc: 0.05%, Ru: 12%, and Pt as the balance;

[0077] The remaining steps are the same as in Example 9.

[0078] Example 12

[0079] Step 1: Prepare the ingredients by weight percentage: Y: 0.01%, Sc: 0.14%, Ru: 15%, Pt balance;

[0080] The remaining steps are the same as in Example 9.

[0081] Embodiment 13

[0082] Step 1: Prepare the ingredients by weight percentage: Y: 0.14%, Sc: 0.01%, Ru: 15%, and Pt as the balance; the remaining steps are the same as in Example 9.

[0083] Embodiment 14

[0084] Step 1: Weigh the ingredients by weight percentage: Y: 0.06%, Sc: 0.07%, Ru: 15%, and the balance is Pt; The remaining steps are the same as those in Example 9.

[0085] Comparative Example 1

[0086] Step 1: Weigh the ingredients by weight percentage: Ru: 5%, and the balance is Pt;

[0087] Steps 2 to 6 are the same as those in Example 1

[0088] Comparative Example 2

[0089] Step 1: Weigh the ingredients by weight percentage: Ru: 15%, and the balance is Pt;

[0090] Steps 2 to 6 are the same as those in Example 1

[0091] Comparative Example 3

[0092] Step 1: Weigh the ingredients by weight percentage: Y: 0.13%, Ru: 5%, and the balance is Pt;

[0093] Steps 2 to 7 are the same as those in Example 1

[0094] Comparative Example 4

[0095] Step 1: Weigh the ingredients by weight percentage: Y: 0.13%, Ru: 15%, and the balance is Pt;

[0096] Steps 2 to 7 are the same as those in Example 9

[0097] Comparative Example 5

[0098] Step 1: Weigh the ingredients by weight percentage: Sc: 0.13%, Ru: 5%, and the balance is Pt;

[0099] Steps 2 to 7 are the same as those in Example 1

[0100] Comparative Example 6

[0101] Step 1: Weigh the ingredients by weight percentage: Sc: 0.13%, Ru: 15%, and the balance is Pt;

[0102] Steps 2 to 7 are the same as those in Example 9

[0103] The processing performance of the examples and comparative examples is shown in Table 1

[0104] Table 1

[0105]

[0106]

[0107] The comparison of the strength and hardness of the examples and comparative examples is shown in Table 2

[0108] Table 2

[0109]

[0110]

[0111] Among them, the influence of the ordering heat treatment temperature (heat treatment time is 30 minutes) on the hardness of Example 14 and Comparative Example 2 is shown in Figure 1 .

[0112] To further improve the performance of the Pt-based alloy for spark plugs, while controlling the alloy cost and improving the convenience of the alloy preparation process, the present invention starts from the alloy composition design, strengthens the alloy by adding Y and Sc elements simultaneously, and reduces the alloy cost while ensuring the high melting point of the alloy by adding Ru element. Then, the alloy performance is further improved by ordering heat treatment.

[0113] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for preparing a Pt-based high-temperature alloy material for a spark plug, characterized in that: The following steps are involved: Step 1, Y and Sc are added in amounts of 0.01%-0.15% by weight respectively, the total amount of the two elements added is not more than 0.15%, Ru is added in an amount of 5-15%, and the balance is Pt; Step 2: Y, Sc, Ru, and Pt elements are placed in a crucible, and smelted in a vacuum high frequency furnace. After smelting, the elements are poured into a water-cooled copper mold to obtain an ingot; Step 3: homogenizing the ingot at 1250°C for 4 hours; Step 4: hot forging the ingot at 1250°C to obtain a 6mm diameter bar; Step 5: The rod obtained in step 4 is rolled on a semicircular pass rolling mill to obtain a wire with a diameter of 2 mm. When the total deformation reaches 45%, annealing is performed at 1250° C. for 45 minutes, and quenching is performed in ice salt water after annealing. Step 6: The wire obtained in step 5 is drawn on a multi-mode wire drawing machine to a finished product size of 0.3-0.5 mm; when the deformation per pass does not exceed 8% and the total deformation reaches 45%, annealing is performed at 1200°C for 30 minutes, and quenching is performed in ice salt water after annealing; Step 7: Orderly heat treatment: the hard wire drawn to the finished size is subjected to orderly heat treatment at 750-780°C for 30 minutes.

2. The method for preparing a Pt-based high-temperature alloy material for a spark plug according to claim 1, characterized in that: The crucible is a high-purity zirconia crucible or a cold crucible for suspension smelting.

3. The method for preparing a Pt-based high-temperature alloy material for a spark plug according to claim 1, characterized in that: The 2 mm wire obtained in step 5 has a rolling deformation of no more than 12% per rolling process.

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