US 3715206 A
The invention concerns with highly improved heat resisting Ni-Al-Be alloys.
Claims available in
Description (OCR text may contain errors)
nited States Patent Komatsu et al.
HEAT RESISTING ALLOYS Inventors: Noboru Komatsu; Takatoshi Suzuki;
Takuo Ito, all of Nagoya, Japan Kabushiki Kaisha Toyota Chuo Kenkyusho, Aichi-ken, Japan Filed: July 29, 1970 Appl. No.: 59,169
Foreign Application Priority Data Aug 2, 1969 Japan r v n45l6l344 May 8, l970 Japan ..45/39463 US. Cl ..75/l70, 75/122, 75/134 N,
75/134 F, 148/32 Int. Cl ..C22c 19/00 Field of Search ..75/l70, 171, 150, l38, 122, 75/134 N, 134 F; 148/32, 32.5
51 Feb. 6, 1973  References Cited UNITED STATES PATENTS l,685,570 9/1928 Masing et al. ..75/l70 2,157,979 5/1939 Cooper ct al ..75/l50 2,193,363 3/1940 Adamoli ..75/l50 Primary Examiner-Richard 0. Dean Att0rneySughrue, Rothwell, Mion, Zinn & Macpeak  ABSTRACT The invention concerns with highly improved heat resisting Ni-Al-Be alloys.
The improvement resides in the selection of specific alloying ratios as determined by a certain specific polygonal area plotted on a triangular coordinate diagram of Ni, Al and Be, for general improvement of the high temperature antioxidation performance, high temperature strength and high temperature toughness of the alloys.
4 Claims, 6 Drawing Figures P'ATENTEDFEB ems 3,715,206
SHEET 1 [IF 3 FIG. I
AM/W 6 .51 AAAMWA 9,
O Ola Ni I0 2630 so o so Al,Gt./o
PATENTEDFEB 6 I975 SHEET 2 OF 3 Al, CLO/0 0 O m 5 $89 1 mmmzom MEASURING TEMPERATURE C PATENTEDFEB 6 1975 3,715,206
NW IO W M Ni Al IO 20 3O 4O 5O 60 Al. OT. /0
HEAT RESISTING ALLOYS This invention concerns highly improved heat resisting alloys representing superior antioxydation properties even at higher temperatures, as well as superior high temperature strength and toughness properties.
With modern rapidly developing and expanding technology and industrial manufacture, demands of high temperature heat resisting materials, especially durable to substantially higher temperatures than 1,000C are amazingly increasing. These exceptionally superior heat resisting materials are now demanded for use in the manufacture of rocket shells; atomic heat engine parts; fuel combustion chambers and jet organs of jet-propulsion engines; blades or the like parts of gas turbines; high temperature and high pressure equipments in chemical plants; high temperature valves and the like. These parts and equipments are exposed to very high temperatures and severe loads.
Although until nowadays various and profound studies and investigations have been made for the realization of the heat resistant materials, the following limitation must be imposed in the use of these materials. As an example, the heat resistant steel must be used in practice at a temperature range lower than 800C. Heat resistant alloys containing as its main constituent Ni or C0, the practically usable temperature range will increase to about 1,000C. With higher temperatures than 1,000C, these heat resistant alloys represent generally a substantially reduced strength, as well as abruptly decreased antioxidation properties which tendency prevents these alloys from their prolonged usage.
On the other hand, fire resistant alloys containing Mo, Nb and Ta, and ceramic materials can be used at higher temperatures than 1,000C for a long time. These fire resistant alloys, however, show an inferior antioxidation performance at high temperatures so that the kind, nature and working conditions of the environmental atmosphere are limitative and/or a certain surface treatment for intensifying the antioxidation performance must preferably be applied. 1n the case of ceramic materials, considerable drawbacks will be encountered by the lack of ductility, malleability and shock resistibility, resulting in a liability to destruction when subjected to a sudden and substantial temperature change. lt may therefore be definitely concluded that conventional heat resistant materials when used in various high temperature parts and equipments represent much to be desired and must be further improved.
lt is the main object of the invention to provide such heat resistant alloys as capable of obviating substantially the aforementioned conventional drawbacks.
It is a further object of the invention to provide heat resistant alloys having superior antioxidation performance, mechanical strength and toughness even in a high temperature range between about l,000 and about 1,200C.
1n the progress of our investigation into the development of heat resistant alloys capable of satisfying the above mentioned objects, attention has been directed at first to Ni-Al alloys and Ni Al alloys which means intermetallic compounds as will be referred to hereinafter throughout the present specification, having superior high temperature antioxidation properties. Our investigation has been further directed to improve the high temperature hardness and toughness of the above kind of heat resisting alloys, and, indeed, without inviting any reduction of their superior antioxidation properties.
From the results of a larger number of practical experiments carried out in the above sense, we have found that the ternary Ni-Al-Be alloys which can be produced by adding Be to the binary Ni Al alloys of the above kind and comprise specific alloying ratios lying within an imaginary poligonal areas as determined by specific five apexes drawn on the triangular coordinate chart of said three alloying components: Ni, Al and Be. The first apex is fixed by a specific alloying ratio of Ni 48 at. Al 0.1 at. and Be 51.9 at. this first apex being referred to as l-point" hereinafter throughout the specification. The second apex is fixed by a specific ratio of these three alloying components: Ni 50.1 at. Al 0.1 at. and Be 49.8 at. this second apex being referred to as .l-point" hereinafter. The third apex called K-point" is fixed by a specific ratio of these alloying components: Ni 61 at. Al 1 1 at. and Be 28 at. 1n the similar way, the fourth apex called B- point" is determined by an alloying ratio: Ni 87 at. Al 11 at. and Be 2 at. The fifth apex called C- point is determined by an alloying ratio: Ni 48 at. A at. and Be 2 at.
These alloys will be called hereinafter throughout the specification as the first range alloys. The at.% is meant by atomic percentage which may be abbreviated hereinafter only to When the hardness of the alloy should be evaluated at most, it can be selected from a polygonal area in said triangular co-ordinate chart covered by six apexes of 1, J, K, D, E and C-points. The points 1, .l, K and C are same as before, while the D-point is fixed by an alloying ratio of: Ni 79% Al 1 1% and Be 10% and the 15-point by a ratio of: Ni 71%; Al 27% and Be 2%. These alloys will be referred hereinafter as the second range alloys."
When the antioxidation performance, the hardness and the toughness of the alloy must be evaluated jointly at the most, it can be selected from a polygonal area in said triangular coordinate chart covered, however, by six apexes of F, G, D, E, C and H, of which the three D, E- and C-points are same as before, while the F- point is determined by a specific alloying ratio: Ni 51%; Al 14% and Be 35%; the 6-point by: Ni 69%; Al 11% and Be 20%; and the H-point by: Ni 48%; Al 39% and Be 13%, as will be more fully described hereinafter. These alloys will be referred to as the third range alloys throughout the specification.
Further, when the relative strength of the alloy should be highly evaluated, it can be selected from a polygonal area in said triangular coordinate chart covered, however, by four apexes of A-, l-, J and 1(- points, of which the first or A-point is determined by a specific alloying ratio: Ni 48%; Al 11% and Be 41%, while the remaining three points 1, J and K are same as before. These alloys will be referred to hereinafter throughout the specification as the fourth range alloys."
These and further objects, features and advantages of the invention will become more apparent when read the following detailed description of the invention by reference to the accompanying drawings illustrative of several preferred embodiments thereof shown only by way of examples.
In the drawings:
FIG. 1 is a Ni-Al-Be triangular coordinate diagram showing a plurality of test specimen alloys used in the experiments carried out on heat resistant Ni-AlBe als.
FIG. 2 is a Ni-AlBe triangular coordinate diagram showing several different areas of oxidation weight increase of Ni-Al-Be alloyes appearing on the said diagram.
FIG. 3 is a Ni-Al-Be triangular coordinate diagram showing several different areas of room temperature hardness of Ni-Al-Be alloys appearing on the said diagram.
FIG. 4 is a chart of the harness of various alloying materials used for the preparation of the heat resistant Ni-Al-Be alloy according to the invention, being plotted against measured temperature.
FIG. 5 is a Ni-AlBe triangular coordinate diagram showing several different areas of toughness of Ni-Al-Be alloys appearing on the said diagram.
FIG. 6 is a NiAl-Be triangular coordinate diagram showing several different composition ranges of the heat resisting alloys proposed by the present invention.
All the triangular coordinate diagrams shown are prepared in the form of regular triangles. All the sides of each of these triangular diagrams have corresponding scales of the arithmetical order.
' As seen, the left-hand and right-hand sides represent the nickel content and the beryllium content, respectively, while the bottom side represents the aluminum content.
In the experimental preparation of the Ni-Al-Be heat resistant alloys according to this invention, the alloying materials were electrolytic nickel, high purity aluminum, metallic beryllium, Ni-Be alloy and Al-Be alloy. These materials were melted together by a specifically selected melting process to be described below and then moulded into samples which were subjected to tests.
On account of large affinity of beryllium with oxygen, the alloying materials were melted in a specific vessel relying upon the floatation principle, in order to avoid the formation of oxidation impurities.
As the melting atmosphere, argon was used after addition of a small quantity of hydrogen, for avoiding otherwise encountered oxydation. The molten alloy was cast into a copper moulds.
For the determination of the inventive alloying range, we have prepared about 80 kinds of the ternary alloys comprising Ni, Al and Be, of which several representatives are shown in FIG. 1. The nature of this triangular coordinate diagram is quite obvious from the foregoing disclosure by any person skilled in the art. As an example, a specific point shown at Y" represents an alloy consisting of Ni 30%; Al 40% and Be 30%. The test specimens shown have respective nickel contents higherthan about 30%; aluminum contents lower than about 65 and beryllium contents lower than about 50%. Specimens having other alloying ratios have been omitted from the drawing, since it has been acknowledged by experiments that these outsiders do not represent the disired effects.
By use of these specimens, the antioxidation performance was investigated.
In this case, the specimen of 8 mm 41, 5 mm long was measured by weighing it on a chemical balance in units of 0.01 mg. Then, the specimen is put on a ceramic boat made of alumina and kept at 1,200C for 5 hours in an electric furnace, and cooled down in open air atmosphere. The specimen was weighed again and the weight increase was determined. These values were expressed in terms of weight increase, mg, divided by the surface area of the specimen, cm and classified into four categories as shown in the following Table l. The results are also shown graphically in FIG. 2, as attached respectively with l, m, n and 0.
Table 1 Ranges of Oxydation Weight Symbols Increase (mg/cm) expressed in FIG. 2
less than 0.49 1" 0.50 to 0.99 m higher than 1.0 "n" melted at 1,200C. "0"
The practical values of oxidation weight increase of those alloys having a ratio: Be about 30 53%; Ni about 45 60% and lying in the range area of n in For comparison, the conventional heat resisting alloy NEMONIK was tested simultaneously, showing an oxidation weight increase of 3 mglcm With increase of the oxydation weight increase value, the antioxydation property of the alloy will naturally become inferior. It is therefore definitely seen that the Ni-Al-Be alloy according to this invention has substantially superior antioxidation performance over conventional heat resisting alloys.
In FIG. 2, a Ni A1 alloy having a ratio of: Ni 50% and Al 50%, and a Ni Al alloy having a ratio of: Ni and A1 25%, are also shown. These conventional alloys are also plotted on other triangular coordinate diagrams shown and to be described.
Next, the room temperature hardness tests were performed with the test specimens of the inventive alloy on a Vickers hardness tester with a load of 5 kg. The thus measured values, I-Iv, are grouped into five ranges according to the schedule shown in the following Table 3. The same results are graphically shown in FIG. 3.
Table 3 Corresponding Range of Hardness, Hv Symbols shown in FIG. 3
In consideration of the similar tests on the conventional alloys Ni Al (I-IV: 330) and Ni Al (Hv: 220), the superior effect obtained by the addition of beryllium will be obvious from the foregoing.
Next, the relationship of the inventive alloys between the hardness and the temperature was experimentally investigated, partially based upon the foregoing hardness tests.
For this purpose, nine kinds of specimens Kl K7, K Kll shown in the following Table 4 were selected out from the four room temperature hardness ranges q, r, s" and t. These samples are also plotted on the diagram in FIG. 3 as attached with same specimen symbols.
In the progress of the experiments, the specimen was heated up to 1,200C and the hardness was measured at each temperature increase increment of 100C on a Vickers micro-hardness tester loaded with 300 grs.
The test results are plotted on the chart shown in FIG. 4 which has been prepared with a logarithmic hardness scale, l-lv, and an arthmetic temperature scale, C, as shown.
For comparison, a specimen, K of conventional heat resisting steel SUH31B (JIS Japanese Industrial Standards) and a further specimen, Specimen K Haynes Stellite Superalloy H825 of cobalt base, the both alloys being highly well known in Japan as of superior high temperature hardness, were simultaneously tested and the results are also shown in FIG. 4.
Table 4 Specimen Composition, at.
It will be clearly observed from FIG. 4, those which have been prepared by adding beryllium to Ni-Al alloys and having a superior room temperature hardness over Hv: 400, represent more improved high temperature hardness than that of the basic binary alloys, the novel alloy keeping its room temperature hardness until about 700C. The novel alloys when they have Hvvalues 750-850 at room temperature, they can keep these values until about 900C. Therefore, the addition of beryllium provides a substantial technical advantage also in the above sense at substantial high temperatures, as ascertained from the test results of specimens K4 and K5.
When comparing with the hardness of conventional heat resisting steel and -alloy, Specimens-K8 and -K9, the novel Ni-Al-Be alloys K2 K7 and K10 K1 1, represent three to five times higher values of room temperature hardness.
When considering the fact that the conventional alloys as representatively expressed by Specimens K and K show a rather inferior maximum allowable temperature of 800 900C for keeping its hardness Hv: 100. In the case of the novel ternary alloys, even when considering those representing rather appreciable hardness variation in function of temperature variation, such as in the case of the Specimens K and K the maximum allowable temperature amounts to higher than 900C for representing the hardness lower than Hv 100. In the case of the Specimens K and K-,, the critical temperature value amounts to as high as 1,000 1,100C.
In the case of the still improved alloys having a higher percentage of beryllium content, such as Specimens K and K and the hard Specimens K and K having room temperature hardness Hv: 750 850, can represent I-Iv even at 1,200C. It can be thus concluded that the improved alloys according to this invention, when having a superior room temperature hardness in the order of Hv 400 or higher, can show I-lv 100 even at 900C which performance is substantially superior over the comparative conventional heat resisting alloys.
Those of novel alloys which have over HV 600 or a higher beryllium content represent not only superior room temperature hardness, but also substantially improved high temperature hardness over the conventional alloys.
Our investigation was continued on the problem of the toughness. For this purpose, test experiments were carried out in the conventional way as frequently adopted for the determination of the toughness of the cemented hard alloys. More specifically, the specimen was impressed on a Vickers hardness tester and the critical load was measured when cracks appeared around the formed impression. When the critical load is smaller, the stock is naturally of lesser toughness.
In a number of experimental tests of the novel Ni-Al-Be alloys, the impressing load applied on to the specimen was varied successively from 1 through 5, I0, 20 and 30 to 50 kgs., and at each specific load application, three impressions were formed on the specimen so as to well investigate possible development of cracks around each of the impressions. When cracks should be found around even one of these impressions, the degree of toughness of the alloy was determined in terms of the load, X kgs. implied at that time.
The thus measured results were classified into successive five ranges as appearing in the following Table 5. These classified ranges are graphically shown on the triangular coordinate diagram shown in FIG. 5.
Table Classified Ranges of Corresponding Symbols Applied Loads, X in kgs. Shown in FIG. 5
Higher than 50 i 14" In the first line of Table 5, the expression higher than 50 means that no cracks were observed around each of three impressions formed under the impression load of 50 kgs.
As will be observed from FIG. 5, the toughness increases generally with decrease of aluminum content. It will be further observed from the diagram that the addition of beryllium to the corresponding binary Ni-Al alloys can provide a substantial improvement in the toughness of the alloy.
As the alloying material for supplying Ni-, Aland Becomponent, electrolytic nickel, high purity aluminum, metallic beryllium, nickel-beryllium alloy and aluminum beryllum alloy were used, which may, however, include small amounts of Fe, Si, Cu, Co and the like impurities. In the above experiments, these impurities amount only to 0.2 0.4 percent in total. Thus, these material contained practically no contents of impurities. It should be, however, noted that the use of such high purity alloying materials was made only for best control of the alloy components which does not means that an inclusion of impurities gives always rise to the formation of inferior heat resisting alloys.
In the following, the technical reasons for adopting the specifically selected alloying range as was defined hereinbefore will be described hereinbelow more in detail.
For the selection of the limited and specific alloying ratios for the first range alloys, the hardness, the toughness and the oxidation weight increase less than 2.0 mg/sq. cm were considered in combination.
As for the nickel content, it was observed a melting of the alloy in proximity of 1,200C with the nickel content less than 45 percent. In this case, the toughness and hardness were found inferior. The melting phenomenon was observed in the range o." When considering the lower limit of nickel content from these consideration, the limit should preferably placed at the border line between m and n range areas.
From this reason, the lower limit of nickel content was selected to 48 percent which is defined by the line C-I shown in FIG. 6, said line passes through the 1'!- point as defined by the ratio: Ni 48%; AI 39% and Be 13%. Throughout the both ranges m, and n, the most apparent inferior antioxidation performance of the alloy having been observed at this point H, as may be well observed from FIG. 2.
As for the aluminum content, a melting phenomenon was observed at a temperature in proximity of about 1,200C when the Al-content was selected to less than 9 percent with the nickel content amounted to over about 61 percent. It was observed that throughout the combined overall area covering 1-, n and 0"- ranges the most inferiority of antioxidation was observed at G-point shown in FIG. 2 which was defined by the alloy ratio of: Ni 69%; Al 11% and Be 20%, as was referred to hereinbefore. Therefore, with the nickel content higher than about 61 percent, the lower limit of aluminum content was selected to 11 percent which corresponds to the line B-K in FIG.6.
With the nickel content less than about 61 percent and with a higher content of beryllium, the range of the oxidation weight increase set to less than 2.0 mg/sq. cm lies rightwards from a specific point a in F1G.2, as may be well supposed from the tests on Specimens n, n,,, the rightward area relative to n representing more high aluminum contents of the inventive alloys. From this reason, the lower limiting border for attaining the oxidation weight increase set to less than 2.0 mg/sq. cm with the nickel content less than about 61 percent was fixed by the limiting line J-K shown in FIG. 6. The line J-K is defined by the two points of Ni 50% and Be 50%; and Ni and Al 25%. Point J and K are defined by the specific alloying ratios of Ni 50.1%, A1 0.1% and Be 49.8%, and Ni 61.0%, A1 11.0% and Be 28.0%, respectively.
As for the beryllium content, addition of a small quantity of Be can improve the aforementioned performance. When considering, however, mainly the toughness, this property will become inferior with such alloying ratio as of Ni 64-72%; Al 2836% and Be less than 2% which range is shown by the area Y in FIG. 5, over that of the conventional Ni Al alloys which are represented by the aforementioned area X. Upon considering these facts, the lower limit of Be was set to 2 percent, as being expressed by the straight line B-C in FIG.6.
With the range of substantially higher content of Be, it was found that the desired purpose can only be attained with the aluminum content higher than 0.1 percent. From this reason, the lowest limit of Al was set to 0.1 percent, as represented by the straight line I-J in FIG. 6.
From the above various considerations for attaining satisfactory superior performances of toughness and normal and high temperature hardness and, indeed, with the oxidation weight increase set to less than 2.0 mg/sq. cm, the overall alloying range was limited by those lying within the polygonal area defined by the specific points C, I, J, K and B in FIG. 6. These points correspond to specifically selected alloying ratios, as was described hereinbefore.
These alloys called the first range alloys, as was referred to hereinbefore, represent similar or somewhat inferior antioxidation performance in comparison with that of Ni Al or Ni Al alloys which are known to have the most efficient antioxidation performance. These novel alloys, however, represent highly superior hardness and toughness properties in combination. When, therefore, reviewing the overall performance regarding said three kinds of desirous properties, these novel alloys have a preferential performance over the conventional heat resisting alloys and can find their way of utilization as the high pressure, high temperature, high load, and thus highly valuable material in the manufacture of steam and gas turbines, jet propulsion engines, rockets, chemical plant facilities and/or the like.
Next, referring to the second range alloys, it will be easily observed from the foregoing disclosure that the higher nickel content alloys included in q-range in FIG. 3, represent normal temperature hardness less than Hv 399, and somewhat inferior high temperature hardness. When, therefore, deleting these alloys from the aforementioned overall alloying range suggested by the novel teaching of the invention, the remaining alloys represent superior room temperature hardness higher than I-Iv 100. Therefore, these alloys can be effectively utilized as the high temperature hardness material for use in the manufacture of cutting tools, turbine blades, -disks and the like parts which must be highly of the heat resisting nature. These alloys corresponds to the second range alloys defined above. In this case, the range area IJK-DE-C-I includes all the second range alloys. The point D was fixed by the intersection point between the curved line connecting a first point corresponding the alloying ratio of Ni 79% and Be 21% to a second point corresponding to Ni 68% and Al 32% in FIG. 3, representing the room temperature hardness of I-Iv 400, and the straight line connecting the two points K and B. The points E was fixed by the intersection point of the said first curved line with the third straight line connecting two points B and C, instead of the above points K and B in the foregoing. The selection of these points can be easily understood by observing FIG. 3 in combination with FIG. 6.
The q-range area in FIG. 3 showing the alloy ratios of: Ni 48-58%; Al 42-52% and Be smaller amounts, representing the hardness less than Hv 399, defines such alloys having a maximum beryllium content of about 1.8 percent and thus being deleted from inclusion within the second range alloy group.
Next, the third range alloys will be described more in detail.
When the novel alloys belonging to the first range are used as the material in the manufacture of such highly heat resisting parts and devices as gas turbine nozzles, combustion chamber material of that kind of turbine, suction and discharge or exhaust gas valves of automotive drive engine, various high pressure and high temperature parts of chemical and/or industrial plants, blades of jet propulsion engines, they must represent superior antioxidation performance, hardness and toughness in combination. In this case, the oxydation weight increase should preferably be less than 1.0 mg/sq. cm. The room temperature hardness must preferably be higher than H 400 from the same reason as that referred to hereinabove in connection with the second range alloys.
The toughness should be higher than that of the conventional Ni-Al alloy.
In order to satisfy these various and more severe operating conditions, it is recommendable to utilize the third range alloys according to this invention.
For satisfying the superior toughness as required above and over that of conventional Ni-Al alloys, and the hardness requirement of higher than H,,399, the second range alloys could be utilized to a satisfying degree.
It will be observed from the foregoing, however, that these alloys can not satisfy the required antioxidation performance, should the alloys contain more abundant content of beryllium, thereby representing a higher rate of oxidation weight increase such as 1.0 mg/sq. cm. From this reason, those alloys which belong to n range area have been removed from the second range alloys and only those alloys covered by a still reduced polygonal area defined by several specific points F, G, D, E, C and H are recommended to use for the above purpose. F-point is defined in the range I by selecting a specific alloying ratio of: Ni 51%, Al 14% and Be 35%, as was referred hereinbefore, which corresponds to the maximum beryllium content in this range I. The discarded alloy range is defined thus by a polygonal area having its apexes constituted by several specific alloying ratio points F, H, I, J, K and G.
When the novel Ni-Al-Be alloys should be used for the manufacture of such machine parts as of turbine blades, aircraft and rocket shells and the like which require a high relative strength, those alloys having a high beryllium content should preferably be selected. For satisfying these requirement, such alloys which are covered by the still reduced polygonal area A-I-J-K-A can advantageously be used. The A-point is defined as an intersecting point of an extension of the straight line. B-K with the line C-I. These alloys are defined as the fourth range alloys, as was referred to hereinbefore. The density of these alloys amounts to about 5.8 6.8 g/cub. cm which is substantially lower than these of the conventional heat resisting steel and alloy amounting generally to 8 9 g/cub. cm. The high temperature hardness and toughness are higher thanconventional, thus providing higher value of relative strength.
We have investigated further by carrying out a plu rality of experiments and found that less than half of the nickel content may be replaced by Fe or C0, so far as the contents of Be and Al are reserved as before. In this case, the hardness value can be increased, while the antioxidation performance and the toughness of the alloy are somewhat reduced. A sample of these quaternary alloys may be: Ni 25%; Co 25%; Al 38%, Be 12%. In comparison with Hv 550 of room temperature hardness of the ternary alloy, the quaternary alloy represents, by way of example, Hv 700. C0 can be replaced by the corresponding amount of Fe. The nature and behavior of these are substantially same as those of the Co-replaced alloys.
The novel Ni-Al-Be alloys according to this invention do not mean in any way the pure ternary alloys which may, however, contain a small mount of impurities, so far as they do not affect upon the desired effects adversely to a detrimental degree. The novel alloy may include, among others, a small amount of impurities such as Fe, Si, Cu, Co and the like which are frequently included as impurities in the commercialized metallic nickel, metallic aluminum, metallic beryllium, nickelberyllium alloy, aluminum-beryllium alloy, aluminumberyllium alloy.
According to our experiments, inclusion of these impurities, such as Fe less than 1.0 wt. CuO less than 3.0 wt. and a trace of Co as frequently contained in commercial metallic nickel (Grade 3,.11S), Fe less than 1.5 wt.%; Si less than 1.5 wt. and a trace of Cu as frequently contained frequently in commercial metallic aluminum (Grade 4, HS), various small amounts of Fe, Na, Cu and the like contained frequently in commercial metallic beryllium, small amounts of Fe, Si, Cu and the like frequently contained in commercial aluminumberyllium alloy, and/or small amounts of Fe, Cu, Co and the like frequently contained in commercial nickelberyllium alloy do not affect adversely upon the desired and advantageous properties of the novel ternary alloy according to this invention.
It will be seen from the foregoing that in the practice of the invention, the alloying materials are not limited to those which have been demonstrated in the foregoing detailed description and commercially available alloying materials such as metallic nickel, metallic aluminum, metallic beryllium and alloys thereof can well be utilized within the framework of the invention.
in the foregoing detailed description, the percentages of the alloying elements have been represented in atomic percentages, if not otherwise noted.
In the following Table 6, the atomic percentages as found at the several foregoing critical points A, B, C, D, E, F, G, H, I, J and K have been shown in comparison with the corresponding wt. percentages of the alloying elements.
The embodiments of the invention in which an exclu- 51.9 at the second one being defined by a second alloying ratio ofNi 50.1 at A 0.1 at and Be 49.8
at the third one being defined by a third alloying ratio of Ni 61 at Al 11 at and Be 28 at.%, the
fourth one being defined by a fourth alloying ratio of Ni 87 at.%; Al 11 at.% and Be 2 at.%, and the fifth one being defined by a fifth alloying ratio of Ni 48 at.%; Al 50 at.% and Be 2 at.%.
2. A heat resisting alloy consisting essentially of Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a triangular coordinate diagram of Ni, Al and Be, the polygon having six apexes of which the first one being defined by a first alloying ratio of Ni 48 at.%; A] 0.1 at.% and Be 51.9 at.%, the second one being defined by a second alloying ratio of Ni 50.1 at.%; A1 0.1 at.% and Be 49.8 at.%, the third one being defined by a third alloying ratio of Ni 61 at.%; Al 11 at.% and Be 28 at.%, the fourth one being defined by a fourth alloying ratio of Ni 79 at.%; Al 11 at.% and Be 10 at.%; the fifth one being defined by a fifth alloying ratio of Ni 71 at.%; Al 27 at.% and Be 2 at.% and the sixth one being defined by a sixth alloying ratio of Ni 48 at.%; Al 50 at.% and Be 2 at.%.
3. A heat resisting alloy consisting essentially of Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a triangular coordinate diagram of Ni, Aland Be, the polygon having six apexes of which the first one being defined by a first a1- loying ratio of M51 at.%; Al 14 at.%and Be 35 at.%; the second one being defined by a second alloying ratio of Ni 69 at.%; Al 11 at.% and Be 20 at.%, the third one being defined by a third alloying ratio of Ni 79 at.%; Al
11 at.% and Be 10 at.%, the fourth one being defined.
by a fourth alloying ratio of Ni 71 at.%; Al 27 at.% and Be 2 at.%, the fifth one being defined by a fifth alloying ratio of Ni 48 at.%; Al 50 at.% and Be 2 at.% and sixth one being defined by a sixth alloying ratio of Ni 48 at.%; Al 39 at.% and Be 13 at.%.
4. A heat resisting alloy consisting essentially of Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a triangular co-ordinate diagram of Ni, Al and Be, the polygon having four apexes of which the first one being defined by a first alloying ratio of Ni 48 at.%; Al 11 at.% and Be 41 at.%, the second one being defined by a second alloying ratio of Ni 48 at.%; A1 0.1 at.% and Be 51.9 at.%, the third one being defined by a third alloying ratioof Ni 50.1 at.%; A1 0.1 at.% and Be 49.8 at.% and the fourth one being defined by a fourth alloying ratio of Ni 61 at.%; Al 11 at.% and Be 28 at.%.