JP6607680B2 - Mo-added Ni-based intermetallic compound alloy and method for producing the same - Google Patents

Description

  The present invention relates to a Mo-added Ni-based intermetallic compound alloy having a two-phase structure and a method for producing the same.

As a structural material that can improve the properties such as hardness and strength of the structural material and reduce the weight of the structural material, there are two overlapping layers having a Ni ₃ Al (L1 ₂ ) phase and a Ni ₃ V (D0 ₂₂ ) phase. Development of a Ni-based intermetallic compound alloy having a phase structure is underway. Specifically, the double-duplex structure is composed of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure, and is composed of an intermetallic compound phase having a close packed structure. For this reason, the Ni-based intermetallic compound alloy having a two-phase structure has significantly superior ductility and toughness as compared with a single-phase intermetallic compound material, and exhibits good hardness and strength even in a high temperature environment.

  In addition, since the Ni-based intermetallic compound alloy includes Ni as a main constituent element and contains Al or V that is lighter (smaller in atomic weight) than Ni, it can be compared with other Ni alloys and the like. Light weight. In the following description, Ni, Al, and V are also referred to as basic constituent elements of the Ni-based intermetallic compound alloy.

  In such a Ni-based intermetallic compound alloy, further improvement in characteristics is desired for practical use. Therefore, for example, Patent Document 1 proposes a Ni-based intermetallic compound alloy in which Nb is added as a basic constituent element, in particular, in order to improve the strength under a high temperature environment. Further, Patent Documents 2 and 3 propose Ni-based intermetallic alloy in which elements such as Ta and Re are added as basic constituent elements in order to improve the hardness particularly.

Republished WO2007 / 086185 Republished WO2012 / 039189 JP 2009-215649 A

However, even if Nb is added to the Ni-based intermetallic compound alloy as described in Patent Document 1, there is an upper limit on the strength that can be increased. This is because even if Nb is added beyond the solid solubility limit, Nb in excess of the solid solubility limit is present as a Ni ₃ Nb phase and does not contribute to improvement in strength or the like. .

  In order to increase the strength and the like exceeding the above upper limit, it is conceivable to add, for example, Ta described in Patent Document 2 together with Nb. However, in this case, since Nb and Ta, which are the same elements, are added simultaneously, the strength of the Ni-based intermetallic compound alloy is increased in a superimposed manner according to the combined value of the solid solubility limit of each element. I can't. That is, even if Nb and Ta are added simultaneously, the strength of the Ni-based intermetallic alloy remains at the strength corresponding to the solid solubility limit of any element.

  For this reason, it cannot be expected to obtain the effect of increasing the strength by adding Nb and the effect of increasing the strength by adding Ta, in other words, by adding the effects of solid solution strengthening by adding each element. Further, an element added beyond the solid solubility limit of any of the above elements may form a phase that hinders the strength increase of the Ni-based intermetallic compound alloy. Therefore, eventually, it is difficult to improve the strength of the Ni-based intermetallic alloy beyond the upper limit.

  In addition, Ta, Re, and the like have a larger atomic weight than Ni, Al, and V, which are basic constituent elements. For this reason, as described in Patent Documents 2 and 3, there is a concern that adding Ta, Re, or the like to the Ni-based intermetallic compound alloy may cause an increase in density, which is not preferable from the viewpoint of suppressing an increase in weight. .

  The present invention has been made to solve the above-described problems, and provides a Mo-added Ni-based intermetallic compound alloy capable of improving hardness and strength while suppressing an increase in weight and a method for producing the same. For the purpose.

In order to achieve the above object, the present invention is a Mo-added Ni-based intermetallic compound alloy having a _double- phase structure composed of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure. In addition, Ni, Al, and V in a composition region that forms the double-duplex structure are included as basic constituent elements , and Ni: 75.0 at%, Al: 10.0 at% as the composition region that forms the double-duplex structure V: The content of at least one of the basic constituent elements of 15.0 at% is the amount of addition of 3.0 to 4.0 at% Mo and 0.0 to 3.0 at% Nb by subtracting et al is, Ni: 71.0~75.0at%, Al: 6.0~10.0at%, V: 8.0~15.0at%, Mo: 3.0~4.0at%, The total composition composed of Nb: 0.0 to 3.0 at% is 100.0 at%. It is characterized by. In the present specification, “at%” indicates atomic percent.

The Mo-added Ni-based intermetallic compound alloy according to the present invention has a _double- duplex structure composed of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure. Here, L1 ₂ phase is Ni ₃ Al, D0 ₂₂ phase is Ni ₃ V.

  In other words, this Mo-added Ni-based intermetallic compound alloy contains Ni, Al, and V, which are basic constituent elements, so as to be in a composition range capable of forming the above two-phase structure. Examples of such a composition range include Al: 5.0 to 13.0 at%, V: 10.0 to 18.0 at%, Ni: 60.0 at% or more (remainder).

  In addition, the Mo-added Ni-based intermetallic compound alloy according to the present invention is added with Mo by reducing the content of at least one of the basic constituent elements. That is, in this composition, at least one element of Ni, Al, and V is replaced with Mo, so that the total composition including at least the basic constituent element and Mo is 100.0 at%.

  Thus, in the Mo-added Ni-based intermetallic compound alloy according to the present invention to which Mo is added, for example, compared with a Ni-based intermetallic compound alloy in which only Nb is added as a basic constituent element, hardness and strength ( Tensile strength) can be effectively improved. Further, since the atomic weight of Mo is 95.94, it is significantly smaller than the atomic weight of Ta (180.95) and the atomic weight of Re (186.21). For this reason, in the Mo-added Ni-based intermetallic compound alloy according to the present invention, it is possible to avoid an increase in density as in, for example, a Ni-based intermetallic compound alloy to which Ta or Re is added.

  From the above, the Mo-added Ni-based intermetallic compound alloy according to the present invention can improve the hardness and strength while suppressing an increase in weight, that is, an increase in density.

  In the Mo-added Ni-based intermetallic compound alloy, it is preferable that the total of the composition further including Nb is 100.0 at%. Thus, even if Mo and Nb are added together in the Ni-based intermetallic compound alloy, it is possible to avoid the occurrence of mutual interference (interaction) because Mo and Nb are not in the same family.

  Therefore, the effect of adding the solid solution strengthening of Mo and Nb is added, in other words, the effect of increasing hardness and strength by adding Mo and the effect of increasing hardness and strength by adding Nb are superimposed. Can be obtained. That is, the hardness and strength of the Mo-added Ni-based intermetallic compound alloy can be increased beyond the upper limit that can be increased by adding Nb. For this reason, as described above, it is possible to obtain a Mo-added Ni-based intermetallic compound alloy that is lightweight and has improved hardness and strength more effectively.

  In the Mo-added Ni-based intermetallic compound alloy, it is preferable that Mo is added after the content of Ni or the content of basic constituent elements other than Ni and Ni is reduced among the basic constituent elements. . Thus, by reducing at least Ni among the basic constituent elements and adding Mo, the strength and ductility of the Ni-based intermetallic alloy according to the present invention can be effectively improved. Also, depending on the type of other basic constituent elements that are reduced together with Ni, different characteristics are improved, whereby Mo-added Ni-based intermetallic compounds having various strengths and ductility can be obtained.

  In the Mo-added Ni-based intermetallic compound alloy, the Mo content is preferably 0.5 at% to 4.0 at%. When the Mo content is within the above range and not more than the solid solubility limit, solid solution strengthening can be effectively achieved. On the other hand, when the Mo content is within the above range and is not less than the solid solubility limit, precipitation strengthening by the third phase (precipitate) can be further superimposed in addition to the solid solution strengthening. .

  In the Mo-added Ni-based intermetallic compound alloy, it is preferable that among the basic constituent elements, the Ni content or the Ni and V contents are reduced and 3.0 at% Mo is added.

Here, the pro-eutectoid L1 ₂ phase Mo added Ni-based intermetallic compounds in the alloy is substantially cubic shape, the channel portion is a gap between the該初analysis L1 ₂ phase, (L1 ₂ + D0 ₂₂₎ eutectoid organizations Is formed. As described above, in the Mo-added Ni-based intermetallic compound alloy having a composition in which the content of Ni or Ni and V is reduced and 3.0 at% Mo is added, the third phase is precipitated in the channel portion. be able to. The third phase is a different phase from the L1 ₂ phase and D0 ₂₂ phase, which contributes to the improvement of hardness and strength. Therefore, by precipitating the third phase as the above composition, the hardness and strength of the Mo-added Ni-based intermetallic compound alloy can be more effectively increased.

In the following description, the structure composed of the proeutectoid L1 ₂ phase and the channel part is also referred to as the upper multiphase structure, and the (L1 ₂ + D0 ₂₂ ) eutectoid structure is also referred to as the lower multiphase structure.

  In the Mo-added Ni-based intermetallic compound alloy, it is also preferable that Mo is added after the Al content or the V content is reduced among the basic constituent elements.

  The Mo-added Ni-based intermetallic compound alloy preferably further includes B within a range of 10.0 to 1000.0 ppm by weight with respect to the total weight of the composition. In this case, it becomes possible to improve ductility by suppressing grain boundary cracking, and the characteristics of the Mo-added Ni-based intermetallic compound alloy can be further improved.

  A manufacturing method for obtaining the above-described Mo-added Ni-based intermetallic compound alloy is also included in the present invention.

That is, the present invention is a method for producing a Mo-added Ni-based intermetallic compound alloy, comprising Ni, Al, and V as basic constituent elements, and comprising a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure. 2 As a composition region forming a double phase structure, the content of at least one of the basic constituent elements of Ni: 75.0 at%, Al: 10.0 at%, V: 15.0 at% By adding 3.0 to 4.0 at% Mo and 0.0 to 3.0 at% Nb , Ni: 71.0 to 75.0 at%, Al: 6.0 to 10.0 at% V: 8.0-15.0 at%, Mo: 3.0-4.0 at%, Nb: 0.0-3.0 at% Performing a first heat treatment on the alloy to form a single phase of A1 (fcc) phase; The alloy a single phase by precipitating the pro-eutectoid L1 ₂ phase, after the coexisting phase of the pro-eutectoid L1 ₂ phase and A1 (fcc) phase, the A1 (fcc) phase (L1 ₂ + D0 ₂₂₎ co And a step of obtaining a Mo-added Ni-based intermetallic compound alloy having the double-phase structure by performing a second heat treatment so as to change into a deposited structure.

In the method for producing a Mo-added Ni-based intermetallic alloy according to the present invention, first, at least one of the basic constituent elements Ni, Al, and V having a composition range capable of forming a double-phase structure. An alloy having a composition in which the element is replaced with Mo is obtained. And this alloy is made into the single phase of A1 (fcc) phase (Ni solid solution phase) by the 1st heat treatment. Next, the second heat treatment, A1 is precipitated pro-eutectoid L1 ₂ phase from (fcc) phase forming the upper duplex structure, further, A1 remaining in the gap (channel portion) of該初analysis L1 ₂ phase ( fcc) phase was eutectoid transformation to D0 ₂₂ phase and L1 ₂ phase forming the lower duplex structure by.

That is, in the second heat treatment, pro-eutectoid L1 ₂ phase and A1 (fcc) phase and the coexistence region, and both or either of a region where the pro-eutectoid L1 ₂ phase and A1 (fcc) phase and D0 ₂₂ phase coexist After passing through one side, the alloy is cooled to reach the eutectoid temperature or lower. Thereby, it is possible to form a Mo-added Ni-based intermetallic compound alloy having a double-duplex structure composed of an upper multi-phase structure and a lower multi-phase structure.

  In the Ni-based intermetallic alloy according to the present invention to which Mo is added as described above, for example, hardness and strength are higher than those of a Ni-based intermetallic compound alloy in which only Nb is added as a basic constituent element. It can be improved effectively. Further, for example, the density can be reduced as compared with a Ni-based intermetallic compound alloy to which Ta or Re is added. Therefore, by the manufacturing method according to the present invention, it is possible to obtain a Mo-added Ni-based intermetallic compound alloy exhibiting excellent hardness and strength while suppressing an increase in weight.

  In the manufacturing method of the Mo-added Ni-based intermetallic compound alloy, the alloy is obtained by adding Mo after reducing the content of Ni or the content of basic constituent elements other than Ni and Ni among the basic constituent elements. It is preferable to obtain

  In the method for producing the Mo-added Ni-based intermetallic compound alloy, the Mo content is preferably set to 0.5 at% to 4.0 at%.

  In the manufacturing method of the Mo-added Ni-based intermetallic compound alloy, the total of the compositions is 100.000 by adding Mo and Nb while reducing the content of at least one of the basic constituent elements. It is preferable to obtain the alloy having 0 at%. In the Mo-added Ni-based intermetallic compound alloy obtained from this alloy, the effect of increasing hardness and strength by adding Mo and the effect of increasing strength by adding Nb can be obtained in a superimposed manner. For this reason, it is possible to obtain a Mo-added Ni-based intermetallic compound alloy with improved hardness and strength more effectively while suppressing an increase in weight.

  In the manufacturing method of the Mo-added Ni-based intermetallic compound alloy, the alloy may be obtained by adding 3.0 at% Mo by reducing the Ni content or the Ni and V contents among the basic constituent elements. It is preferable to obtain In the Mo-added Ni-based intermetallic compound alloy obtained from this alloy, the third phase can be precipitated in the channel portion, so that the hardness and strength can be increased more effectively.

  In the method for producing the Mo-added Ni-based intermetallic compound alloy, it is also preferable to obtain the alloy by adding Mo with the Al content or the V content being reduced among the basic constituent elements.

  In the method for producing the Mo-added Ni-based intermetallic alloy, the alloy may be obtained by further adding B so as to be in the range of 10.0 to 1000.0 ppm by weight with respect to the total weight of the composition. preferable. In the Mo-added Ni-based intermetallic compound alloy obtained from this alloy, it becomes possible to improve ductility by suppressing grain boundary cracking, and the characteristics can be further improved.

  In the present invention, Mo is excellent in hardness and strength while suppressing an increase in weight by substituting at least one element of Ni, Al, and V in a composition region forming a double-duplex structure with Mo. An additive Ni-based intermetallic compound alloy can be obtained.

It is a schematic diagram for demonstrating the 2 double phase structure | tissue of the Mo addition Ni base intermetallic compound alloy which concerns on embodiment of this invention. It is a longitudinal section state figure about temperature and Al content in Nb content of 3.0 at% about one specific example of a composition system alloy which serves as a basis of Mo addition Ni base intermetallic compound alloy concerning an embodiment of the present invention. It is a SEM observation result of sample a1. It is a SEM observation result of sample b1. It is a SEM observation result of sample c1. It is a SEM observation result of sample a2. It is a SEM observation result of sample b2. It is a SEM observation result of sample c2. It is a SEM observation result of the sample d. It is a SEM observation result of comparative example 1. It is a graph which shows the result of each Vickers hardness test of sample a1, a2, b1, b2, c1, c2, d and the comparative example 1. It is a graph which shows the result of each Vickers hardness test of sample a3, b3, c3 and the comparative example 2. It is a graph which shows the result of each tensile strength measurement of sample a2, b2, c2, d and the comparative example 1. It is an X-ray-diffraction result of sample a2, c2 and the comparative example 1. FIG.

  Preferred embodiments of the Mo-added Ni-based intermetallic compound alloy and the manufacturing method thereof according to the present invention will be described below in detail with reference to the accompanying drawings.

  First, with reference to FIG. 1, a two-duplex structure 16 of the Mo-added Ni-based intermetallic compound alloy 10 according to the present embodiment will be described. In addition, FIG. 1 is a schematic diagram of the two-phase structure 16 and shows a part of the structure in an enlarged manner.

The Mo-added Ni-based intermetallic compound alloy 10 has a double-phase structure 16 composed of a pro-eutectoid L1 ₂ phase 12 and a (L1 ₂ + D0 ₂₂ ) eutectoid structure 14. L1 ₂ phase is Ni ₃ Al, D0 ₂₂ phase is Ni ₃ V. As described above, the Mo-added Ni-based intermetallic compound alloy 10 has a double-phase structure 16 in which two intermetallic compounds having a close-packed structure are formed into a double phase, which is compared to a single-phase intermetallic compound material. Thus, it has excellent ductility and toughness, and can exhibit good strength and hardness even in a high temperature environment.

Also, the pro-eutectoid L1 ₂ phase 12 is substantially cubic shape, the channel portion is該初analysis L1 ₂ phase 12 gaps each other (L1 ₂ + D0 ₂₂₎ eutectoid structure 14 is formed. That is, the double-duplex structure 16 includes an upper multiphase structure composed of the proeutectoid L1 ₂ phase 12 and the channel portion, and a lower multiphase structure composed of the (L1 ₂ + D0 ₂₂ ) eutectoid structure 14. It can be said that there is.

  This Mo-added Ni-based intermetallic compound alloy 10 contains Ni, Al, and V in a composition range in which a double-duplex structure 16 can appear as basic constituent elements (basic constituent elements). Here, as a composition range in which the double-duplex structure 16 can appear, for example, Al: 5.0 to 13.0 at%, V: 10.0 to 18.0 at%, Ni: 60.0 at% That is the above (remainder).

  Then, at least any one of the basic constituent elements in the composition range is reduced and Mo is added, so that the total composition including at least the basic constituent element and Mo becomes 100.0 at%. Yes. That is, it has a composition in which at least one of Ni, Al, and V is replaced with Mo. In addition, it is preferable that the addition amount of Mo shall be 1.5 at% or more, for example.

  The composition may be composed of only the basic constituent element and Mo, and may contain Nb in addition to the basic constituent element and Mo. In this case, the strength of the Mo-added Ni-based intermetallic compound alloy 10 can be further improved by solid solution strengthening with Nb. In addition to the above composition, the Mo-added Ni-based intermetallic alloy 10 may further include B having an effect of improving ductility by suppressing grain boundary cracking.

  The content of Nb or B may be in a range that can effectively improve the strength, ductility, etc. of the Mo-added Ni-based intermetallic compound alloy 10. For example, in the case of Nb, at least any one of the basic constituent elements is reduced so that the total of the above compositions becomes 100, and is within the range of 0.0 to 5.0 at%, more preferably 1. Nb within a range of 0 to 4.0 at% may be added. In the case of B, B in the range of 10.0 to 1000.0 ppm by weight, more preferably in the range of 30.0 to 300.0 ppm by weight is added relative to the total weight of the above composition. Just do it.

  The components other than the basic constituent elements and Mo are not essential components, and may be added as necessary. Further, the Mo-added Ni-based intermetallic compound alloy 10 may contain additive elements other than Nb and B and impurity elements.

  As a method for producing the Mo-added Ni-based intermetallic alloy 10 configured as described above, for example, a melting casting method, a powder metallurgy method, or the like can be employed. Hereinafter, the manufacturing method of the Mo-added Ni-based intermetallic alloy 10 will be described with reference to FIG. FIG. 2 is a longitudinal sectional state diagram regarding a temperature and an Al content at an Nb content of 3.0 at%, regarding a specific example of a composition-based alloy serving as a basis of the Mo-added Ni-based intermetallic compound alloy 10, An axis | shaft shows Al content (%) and a vertical axis | shaft shows temperature (K).

  First, a first heat treatment is performed on the alloy adjusted to the above composition to obtain a single phase of A1 (fcc) phase. The A1 (fcc) phase is an Ni solid solution phase having an fcc structure (having an irregular structure) that does not have a regular structure.

Next, by performing the second heat treatment, A1 (fcc) phase is precipitated pro-eutectoid L1 ₂ phase 12 from further pro-eutectoid L1 gap (channel portion) of the _2-phase 12 the remaining A1 (fcc) phase D0 ₂₂ phase and L1 ₂ phase in co-precipitating transformation. Thus, an upper multiphase structure composed of the proeutectoid L1 ₂ phase 12 and the channel portion and a lower multiphase structure composed of the (L1 ₂ + D0 ₂₂ ) eutectoid structure 14 are formed.

That is, in the second heat treatment, both regions regions coexist with proeutectoid L1 ₂ phase 12 and A1 (fcc) phase, and in which the pro-eutectoid L1 ₂ phase 12 and A1 (fcc) phase and D0 ₂₂ phase coexist or After passing through either one, the alloy is cooled to reach the eutectoid temperature or lower. Thereby, it is possible to obtain the Mo-added Ni-based intermetallic compound alloy 10 having the double-duplex structure 16 composed of the upper double-phase structure and the lower double-phase structure.

  From FIG. 2, for example, the Al content is within the range of 5.0 at% to 13.0 at% (V: 10.0 to 18.0 at%, remaining Ni: 60.0 at% or more). For example, it can be seen that the two-phase structure 16 can be formed relatively easily by performing the first heat treatment and the second heat treatment.

  As a method for producing the Mo-added Ni-based intermetallic compound alloy 10, for example, when a small arc furnace or the like is used, the cooling rate (solidification rate) after the alloy is melted to form a molten metal is relatively high. For this reason, it may be different from the organization illustrated in FIG. Further, as the first heat treatment, a single phase of the A1 (fcc) phase can be obtained by heating the alloy after solidification. As described above, the first heat treatment can be a solution heat treatment for obtaining an A1 single phase structure, and can be a homogenization heat treatment for homogenizing the alloy. Therefore, in the first heat treatment, the heating temperature and the holding time at the heating temperature may be set to be in a range suitable for achieving the above object.

In addition, the second heat treatment can be performed by continuously cooling the alloy after the first heat treatment as described above to the eutectoid temperature at a predetermined rate. That is, the second heat treatment, changing a step of precipitating the pro-eutectoid L1 ₂ phase 12 alloy, the A1 (fcc) phase coexisting with該初analysis L1 ₂ phase 12 (L1 ₂ + D0 ₂₂₎ eutectoid tissue 14 The two-phase structure 16 can be formed by continuously performing the steps.

  In this second heat treatment, the furnace cooling of the alloy may be performed in two stages instead of continuously performing the furnace cooling. That is, as the second heat treatment, first, the alloy is held at a temperature higher than the eutectoid temperature to form an upper multiphase structure, and then the alloy is held at a temperature lower than the eutectoid temperature to form the lower multiphase structure. You may make it form.

  Further, as a method for producing the Mo-added Ni-based intermetallic compound alloy 10, for example, a vacuum induction melting / casting method or the like can be used. In this case, since the cooling rate is relatively low, a single phase of A1 (fcc) phase can be obtained using the cooling process (step) of the solid phase solidified from the molten metal as the first heat treatment.

  Thereafter, the process of continuously cooling the alloy to the eutectoid temperature or lower can be used as the second heat treatment to form each of the upper double-phase structure and the lower double-phase structure. As a result, the Mo-added Ni-based intermetallic compound alloy 10 having the two-phase structure 16 can be obtained.

  In the second heat treatment in this case, the alloy may be cooled in two stages. That is, as the second heat treatment, first, the alloy is held at a temperature higher than the eutectoid temperature to form an upper multiphase structure, and then the alloy is held at a temperature lower than the eutectoid temperature to form the lower multiphase structure. You may make it form.

  Here, the Mo-added Ni-based intermetallic compound alloys 10 having different compositions are manufactured by the manufacturing method using the above-described small arc furnace or the like, and the samples a1 to a3, b1 to b3, and c1 to c3 according to the examples are prepared. , D (hereinafter collectively referred to as samples according to the examples). Further, a comparative Ni-based intermetallic compound alloy was prepared in the same manner as in the Examples except that Mo was not added, and Comparative Examples 1 and 2 were obtained.

  Specifically, in each of the sample according to the example and the comparative examples 1 and 2, as composition ranges in which the double-duplex structure 16 can appear, Ni: 75.0 at%, Al: 10.0 at%, V : 15.0 at% was adopted. Table 1 shows the compositions of the samples according to Examples and Comparative Examples 1 and 2 and the amount of addition of B (wt%) with respect to the total weight of the compositions.

  That is, in the sample a1, the basic constituent element is obtained by reducing Ni among the basic constituent elements in the above composition range, adding 1.5 at% Mo, and reducing V and adding 3.0 at% Nb. The total composition of the elements, Mo and Nb was 100.0 at%. And B was added so that it might become 50.0 weight ppm (0.005 wt%) with respect to the total weight of this composition, and the alloy was obtained.

  For sample a2, an alloy was obtained in the same manner as sample a1 except that the amount of Mo added was 3.0 at%. For sample b1, an alloy was obtained in the same manner as sample a1, except that instead of Ni, Al was reduced and Mo was added. For sample b2, an alloy was obtained in the same manner as sample b1, except that the amount of Mo added was 3.0 at%. For sample c1, an alloy was obtained in the same manner as sample a1, except that instead of Ni, V was reduced and Mo was added. For sample c2, an alloy was obtained in the same manner as sample c1 except that the amount of Mo added was 3.0 at%. For sample d, an alloy was obtained in the same manner as for sample a1 except that Ni and V were reduced by 1.5 at% and 3.0 at% Mo was added.

  Further, in sample a3, by adding 3.0 at% of Mo by subtracting Ni from the basic constituent elements in the above composition range, the total composition of the basic constituent elements and Mo is 100.0 at%. It was. That is, this composition does not contain Nb. And B was added so that it might become 50.0 weight ppm with respect to the total weight of this composition, and the alloy was obtained. For sample b3, an alloy was obtained in the same manner as sample a3, except that instead of Ni, Al was reduced and Mo was added. For sample c3, an alloy was obtained in the same manner as sample a3, except that instead of Ni, V was reduced and Mo was added.

  For each of the alloys obtained as described above, as a first heat treatment, the alloy was held at a heating temperature of 1280 ° C. for 5 hours in a vacuum, and then a temperature reduction rate of 10 ° C./min as a second heat treatment. The furnace was continuously cooled. In this way, samples according to the examples and Ni-based intermetallic compound alloys according to comparative examples 1 and 2 were produced.

  Among these Ni-based intermetallic compound alloys, SEM observation results of samples a1, b1, and c1 are shown in FIGS. 3 to 5, respectively, and SEM observation results of samples a2, b2, c2, and d are shown in FIGS. The SEM observation result of Comparative Example 1 is shown in FIG. In FIG. 6, a part is shown in an enlarged manner.

First, from FIGS. 3 to 10 and the like, any of the Ni-based intermetallic alloy obtained by adjusting the composition of the alloy so as to be in the above-mentioned composition range is the proeutectoid L1 ₂ phase 12 and (L1 ₂ + D0 ₂₂ ). It was confirmed to have a double-overlapping phase structure 16 composed of the eutectoid structure 14.

Moreover, from FIG.6 and FIG.9, Ni content was reduced and sample a2 to which 3.0 at% Mo was added, and Ni and V contents were reduced to add 3.0 at% Mo. and the in sample d, it was confirmed that the third phase 18 different from the channel portion L1 ₂ phase and D0 ₂₂ phase is precipitated.

  Next, the results of Vickers hardness measurement at room temperature for each of samples a1, a2, b1, b2, c1, c2, d and Comparative Example 1 are shown in FIG. Similarly, the results of measuring the Vickers hardness at room temperature for each of Samples a3, b3, c3 and Comparative Example 2 are shown in FIG. Specifically, the Vickers hardness measurement is carried out by performing tests at 10 locations on each of the above samples, calculating an average value of 8 measured values excluding the maximum value and the minimum value from the test, and calculating hardness and hardness. did. The measurement conditions of the micro Vickers hardness meter were a load of 1 kg and a holding time of 10 seconds.

  From FIG. 11 and FIG. 12, it can be seen that the Vickers hardness is increased in all of the samples according to the Examples as compared with Comparative Examples 1 and 2. Moreover, compared with the comparative example 2 which does not contain Nb, in the comparative example 1 containing Nb, the Vickers hardness is increased. It can be seen that the Vickers hardness of the sample is increased.

  Further, in samples a1, a2, b1, b2, c1, c2, and d in which Nb is added together with Mo, the effect of increasing the hardness by adding Mo and the effect of increasing the hardness by adding Nb are obtained in a superimposed manner. be able to. That is, by containing Mo together, the Vickers hardness can be increased beyond the upper limit of the size that can be increased by adding Nb.

  Further, from FIG. 11, among the samples according to the example in which Ni and Al are replaced with Mo, in the samples a2 and b2 in which the Mo content is 3.0 at%, the Mo content is 1.5 at%. It was found that the amount of increase in Vickers hardness was large compared to samples a1 and b1. On the other hand, among the samples according to the example in which V is replaced with Mo, the sample c1 having a Mo content of 1.5 at% is compared with the sample c2 having a Mo content of 3.0 at% compared to the Vickers. It was found that the increase in hardness was large.

Next, a tensile test was performed on each of the samples a2, b2, c2, and d and Comparative Example 1. The size of the test piece used for the tensile test was 2 × 10 × 1.2 mm ³ at the gauge part. The tensile test was performed at room temperature in a vacuum at a strain rate of 1.7 × 10 ⁻⁴ s ⁻¹ . The result is shown in FIG. FIG. 13 is a graph showing the results of a tensile test, showing the relationship between the tensile strength and 0.2% proof stress of each measurement sample.

  From FIG. 13, it can be seen that the tensile strength of all the measurement samples according to the examples is increased as compared with Comparative Example 1. In addition, as described above, in particular, in the samples a2 and d in which the third phase 18 is precipitated in the channel portion, the tensile strength tends to be remarkably increased. In FIG. 13, since the sample a2 is broken in the elastic region, only the value of the tensile strength is shown.

Next, FIG. 14 shows the results of X-ray diffraction performed on the sample c2 and Comparative Example 1 in which the third phase 18 is not precipitated and the sample a2 in which the third phase 18 is precipitated. From FIG. 14, in sample c2 and Comparative Example 1, only diffraction peaks derived from the Ni ₃ Al (L1 ₂ ) phase and the Ni ₃ V (D0 ₂₂ ) phase were observed. In contrast, in the sample a2, in addition to the diffraction peaks derived from L1 ₂ phase and D0 ₂₂ phase, diffraction peaks derived from different third phase 18 and the diffraction peaks were observed. From the X-ray diffraction results, the third phase 18 was identified as an A2 (bcc) structure V-Mo solid solution and / or a tetragonal structure Ni ₄ Mo.

  Similar to sample a2, sample d also has Ni (and V) reduced and Mo is added, and in FIG. 9, as in FIG. 6, the third phase 18 that appears to be a V-Mo solid solution precipitates in the channel portion. doing. Therefore, in the samples a2 and d, the third phase 18 in the channel portion is precipitated, so that precipitation hardening by the third phase 18 occurs in addition to the solid solution strengthening of Mo described above. As a result, as described above, it can be said that the samples a2 and d were able to remarkably increase the strength and hardness.

  From the above, the Mo-added Ni-based intermetallic compound alloy 10 according to the present embodiment exhibits excellent hardness and strength as compared with, for example, a Ni-based intermetallic compound alloy in which only Nb is added as a basic constituent element. . In addition, the Mo-added Ni-based intermetallic alloy 10 to which Mo having a remarkably small atomic weight compared to Ta, Re, etc., has a density similar to that of the Ni-based intermetallic alloy to which Ta, Re, etc. are added. The increase can be avoided. Therefore, the Mo-added Ni-based intermetallic compound alloy 10 exhibits excellent hardness and strength while suppressing an increase in weight, that is, an increase in density.

  In addition, when the Mo-added Ni-based intermetallic compound alloy 10 contains Nb together with Mo, the effect of increasing the hardness and strength by adding Mo and the effect of increasing the hardness and strength by adding Nb can be obtained in a superimposed manner. Can do. That is, the hardness and strength of the Mo-added Ni-based intermetallic compound alloy 10 can be increased beyond the upper limit that can be increased by adding Nb.

  Further, among the basic constituent elements, in the Mo-added Ni-based intermetallic alloy 10 in which the content of Ni or the contents of Ni and V is reduced and 3.0 at% of Mo is added, the channel portion has hardness and The third phase 18 that contributes to the improvement of strength can be precipitated. Therefore, it is possible to increase the hardness and strength more effectively.

  The present invention is not particularly limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Mo addition Ni base intermetallic compound alloy 12 ... Proeutectoid L1 ₂ phase 14 ... (L1 ₂ + D0 ₂₂ ) Eutectoid structure 16 ... 2 double phase structure 18 ... 3rd phase

Claims (10)

Ni, Al, and V in a composition range that has a double-phase structure composed of a pro-eutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure and that forms the double-phase structure are included as basic constituent elements,
As a composition region for forming the two-duplex structure, the content of at least one of the basic constituent elements of Ni: 75.0 at%, Al: 10.0 at%, V: 15.0 at% , 3.0～4.0At% of Mo and 0.0～3.0At% of it is added amount subtracting these Nb, Ni: 71.0~75.0at%, Al : 6.0~10. The total composition of 0 at%, V: 8.0 to 15.0 at%, Mo: 3.0 to 4.0 at%, Nb: 0.0 to 3.0 at% is 100.0 at%. A Mo-added Ni-based intermetallic compound alloy. In Mo added Ni-based intermetallic compound alloy according to claim 1 Symbol placement,
Among the basic constituent elements, the content of Ni or the content of basic constituent elements other than Ni and Ni is reduced, so that 3.0 to 4.0 at% Mo and 0.0 to 3.0 at% Nb are contained. A Mo-added Ni-based intermetallic compound alloy characterized by being added. In the Mo-added Ni-based intermetallic alloy according to claim 1 or 2 ,
Among the basic constituent elements, the content of Ni or the content of Ni and V is reduced, and 3.0 at% Mo and 0.0 to 3.0 at% Nb are added. Added Ni-based intermetallic alloy. In Mo added Ni-based intermetallic compound alloy according to claim 1 Symbol placement,
Among the basic constituent elements, the content of Al or the content of V is reduced, and 3.0 at% Mo and 0.0 to 3.0 at% Nb are added. Base intermetallic compound alloy. In the Mo-added Ni-based intermetallic compound alloy according to any one of claims 1 to 4 ,
A Mo-added Ni-based intermetallic alloy characterized by further containing B in a range of 10.0 to 1000.0 ppm by weight with respect to the total weight of the composition. Ni : 75.0 at%, Al: 10 as a composition region forming Ni, Al, V as basic constituent elements and forming a double-duplex structure composed of a proeutectoid L1 ₂ phase and a (L1 ₂ + D0 ₂₂ ) eutectoid structure. 0.0 at%, V: 15.0 at% Among the basic constituent elements, the content of at least one of the elements is reduced to 3.0 to 4.0 at% Mo and 0.0 to 3.0 at%. Nb : Ni: 71.0-75.0 at%, Al: 6.0-10.0 at%, V: 8.0-15.0 at%, Mo: 3.0-4.0 at %, Nb: obtaining an alloy having a total composition of 0.0-3.0 at% and having a total composition of 100.0 at%, and subjecting the alloy to a first heat treatment to form a single phase of A1 (fcc) phase When,
By precipitating the proeutectoid L1 ₂ phase in the alloy having the single phase, a coexisting phase of the proeutectoid L1 ₂ phase and the A1 (fcc) phase is obtained, and then the A1 (fcc) phase is changed to (L1 ₂ + D0 ₂₂ ) Performing a second heat treatment so as to change into a eutectoid structure, thereby obtaining a Ni-based intermetallic compound alloy having the double-duplex structure;
A method for producing a Mo-added Ni-based intermetallic compound alloy, comprising: In the manufacturing method of Mo addition Ni-based intermetallic compound alloy of Claim 6 ,
Among the basic constituent elements, the content of Ni or the basic constituent elements other than Ni and Ni is reduced, and 3.0 to 4.0 at% Mo and 0.0 to 3.0 at% Nb are added. A process for producing a Mo-added Ni-based intermetallic compound alloy, characterized in that the alloy is obtained. In the manufacturing method of the Mo addition Ni base intermetallic compound alloy of Claim 6 or 7 ,
Of the basic constituent elements, reducing the Ni content or the Ni and V contents and adding 3.0 at% Mo and 0.0 to 3.0 at% Nb to obtain the alloy A method for producing a Mo-added Ni-based intermetallic compound alloy. In the manufacturing method of Mo addition Ni-based intermetallic compound alloy of Claim 6 ,
Among the basic component elements, characterized in that by subtracting the content of the content or V of Al, to obtain the alloy in Rukoto be added 3.0 at% of Mo and 0.0～3.0At% of Nb A method for producing a Mo-added Ni-based intermetallic compound alloy. The method of manufacturing a Mo-doped Ni-based intermetallic compound alloy according to any one of claims 6-9,
A method for producing a Mo-added Ni-based intermetallic compound alloy, wherein the alloy is obtained by further adding B so as to be in a range of 10.0 to 1000.0 ppm by weight with respect to the total weight of the composition.

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