JP4744420B2 - Manufacturing method of high temperature damping manganese-based alloy - Google Patents

Description

  The present invention relates to a high-temperature damping manganese-based alloy whose upper limit of the operating temperature of the damping function is 100 ° C. or more and a method for producing the same.

  Manganese-based alloys have a stable damping function and excellent mechanical properties, and thus are attracting attention as vibration damping alloys that are closest to practical use, and research and development for their practical use are actively promoted. For example, optimizing the composition of the additive metal element of the manganese-based alloy to improve its workability (Patent Document 1) and adding hard second-phase particles to improve the alloy strength (Patent Document 2) Heat treatment (Patent Document 3) for improving moldability and dimensional accuracy before and after heat treatment, heat treatment method (Patent Document 4) of heating manganese-based twin-type vibration damping alloy at a high temperature and then cooling at a constant rate Proposed.

  The damping function of a manganese-based alloy is thought to originate from the twin structure of the alloy. From this, it is considered that the operating temperature range of the damping function of the manganese-based alloy coincides with the temperature range in which the twin structure is formed. The upper limit temperature of the temperature range in which the twin structure is formed is the critical temperature (phase transformation temperature) at which the high temperature γ phase of the manganese based alloy undergoes a transformation to the low temperature γ phase exhibiting twins. The upper limit of the operating temperature range of the damping function is considered to coincide with the phase transformation temperature of the manganese-based alloy. In fact, it has been found that in a manganese-copper alloy, the damping function hardly operates in the temperature range above the phase transformation temperature, and the damping function operates stably in a temperature range lower than the phase transformation temperature. Therefore, it is considered that the upper limit value of the operating temperature of the damping function can be controlled by adjusting the phase transformation temperature of the manganese-based alloy. However, in general, the phase transformation temperature of a manganese-based alloy is adjusted depending on the alloy composition (increased manganese content, etc.) and the conditions in the heat treatment process during manufacturing. However, increasing the manganese content increases the castability of the alloy. Since workability deteriorates, it is not practical. Therefore, in general, the phase transformation temperature is adjusted according to the conditions in the heat treatment process during production. That is, it is considered that the upper limit value of the operating temperature range of the damping function of the manganese-based alloy can be controlled by the conditions in the heat treatment process at the time of manufacture.

Damping alloys are said to have great needs in the fields of engines and power plants for automobiles, aircraft, etc., but in order to be used in these fields, damping materials are used in a high temperature environment of 100 ° C. or higher. The function must work. However, manganese-based alloys such as sonostone alloys (Mn-37Cu-4Al-3Fe-2Ni weight ratio) and inclamute alloys (Cu-45Mn-2Al weight ratio) known as conventional vibration-damping manganese-based alloys Since the phase transformation temperature is lower than 100 ° C., the vibration damping function does not operate under such a high temperature environment. Further, in the conventional manufacturing technique for manganese-based alloys, an aging treatment is performed in which aging is performed for a long time in a high-temperature environment in order to increase the phase transformation temperature. For example, a manganese-based alloy (Mn- (20Cu-5Ni-2Fe atomic ratio) is subjected to an aging treatment for 200 hours in an environment of 400 ° C., the phase transformation temperature is 10
It has been found that it does not exceed 0 ° C. As described above, the conventional manganese-based alloy manufacturing technology cannot increase the phase transformation temperature to 100 ° C. or higher, and can manufacture a manganese-based alloy whose damping function operates in a high temperature environment of 100 ° C. or higher. There wasn't.
Japanese Patent No. 2849698 Japanese Patent No. 3345640 JP 2003-226951 A Japanese Patent Laid-Open No. 2005-23362

  The present invention understands conventional problems from the background as described above, can increase the phase transformation temperature of a manganese-based alloy to 100 ° C. or higher, and exhibits a damping function in a high-temperature environment of 100 ° C. or higher. It is an object to provide a base alloy and a manufacturing method thereof.

  The inventors focused on the fact that the phase transformation temperature of a manganese-based alloy can be improved by controlling the alloy structure of the manganese-based alloy, and conducted extensive studies. As a result, it was found that the phase transformation temperature of the manganese-based alloy can be raised to 100 ° C. or more by distributing the high manganese composition part inside the manganese-based alloy. Previously, it was known that increasing the manganese content would increase the phase transformation temperature, but increasing the manganese content of the alloy would reduce castability and workability, resulting in an impractical alloy composition. It was. However, it is possible to raise the phase transformation temperature of the alloy while maintaining the castability and workability of the alloy by locally generating a portion with a high manganese content without increasing the manganese content of the entire alloy. The present inventors have found out. At a temperature lower than the phase transformation temperature of the manganese-based alloy, the twinning structure is maintained and the damping function operates. Therefore, by raising the phase transformation temperature of the manganese-based alloy to 100 ° C. or higher, the operating temperature of the damping function is reduced. A manganese-based alloy having an upper limit of 100 ° C. or higher is obtained.

  The present invention has been completed based on the knowledge as described above, and has the following characteristics.

First: containing 15 to 25% by weight of copper, 60% by weight or more of manganese, one or more kinds of nickel, iron and aluminum, nickel 0 <Ni ≦ 7% by weight, iron 0 <Fe ≦ 5% by weight, In the method for producing a manganese-based alloy that contains aluminum in the range of 0 <Al ≦ 5 wt% and may contain inevitable impurities, when the raw metal is melted and cooled and cast, 1150 in the cooling step The average cooling rate during cooling from ℃ to 900 ℃ is in the range of 0.05 to 0.5 ℃ / second, and the aging treatment is performed at a temperature in the range of 350 to 650 ℃ for a time in the range of 20 to 50 hours. The manufacturing method of the manganese base alloy characterized by performing these.

Second: Manganese is contained in the range of 60 wt% or more and 70.53 wt% or less, and copper, nickel, and iron are respectively copper 22.35-25 wt%, nickel 5.16-7 wt%, iron 1. In the method for producing a manganese-based alloy containing 96 to 5% by weight and optionally containing unavoidable impurities, when the raw material metal is melt-mixed and cooled and cast, it is 1150 ° C to 900 ° C in the cooling step. The average cooling rate during cooling up to 0.05 to 0.5 ° C./second is applied, and an aging treatment is performed at a temperature in the range of 350 to 650 ° C. for a time in the range of 20 to 50 hours. A method for producing a manganese-based alloy.
Third: Manganese is contained in the range of 60 wt% or more and 70.53 wt% or less, and copper, nickel, and iron are respectively copper 22.35-25 wt%, nickel 5.16-7 wt%, iron 1. In a method for producing a manganese-copper-nickel-iron-based quaternary manganese-based alloy containing 96 to 5% by weight and containing inevitable impurities, the raw material metals are melt-mixed, cooled and cast. In this case, the average cooling rate at the time of cooling from 1150 ° C. to 900 ° C. in the cooling step is in the range of 0.05 to 0.5 ° C./second, and the temperature is in the range of 350 to 650 ° C. for 20 to 50 hours. The manufacturing method of the manganese base alloy characterized by performing the aging treatment of the inside time.

  According to the first invention, the manganese-based alloy contains 15 to 25% by weight of copper and 60% by weight or more of manganese, and one or more of nickel, iron, and aluminum are mixed with 0 to 7% by weight of nickel, Since it contains in the range of 0 to 5% by weight of iron and 0 to 5% by weight of aluminum, the workability of the manganese-based alloy is improved and the vibration damping function operates stably. In the method for producing a manganese-based alloy having the above composition, when the raw metal is melt-mixed and cooled and cast, the average cooling rate during cooling from 1150 ° C. to 900 ° C. in the cooling step is set to 0.05 to 0. By setting the speed within the range of 0.5 ° C./second, the vibration control function operates stably even in a high temperature environment of 100 ° C. or higher.

According to the second aspect of the present invention, a manganese-based alloy having a further improved damping function in a high temperature environment of 100 ° C. or higher is manufactured .
Also, the according to the third aspect, the coefficient output loss at 100 ° C. in a temperature environment of the manganese-based alloy is not less than 0.03, manganese based alloy damping function is further improved under 100 ° C. temperatures higher than Is manufactured .

The manganese-based alloy of the present invention contains 60% by weight or more of manganese. When the manganese content is less than 60% by weight, it is difficult to raise the phase transformation temperature to 100 ° C. or higher because the high manganese composition part cannot be distributed. By setting the manganese content to 60% by weight or more, the high manganese composition part can be distributed inside the alloy, and the upper limit value of the operating temperature of the damping function (in the loss coefficient-temperature graph, the loss coefficient is 0. 0). The temperature at the time of 03. (hereinafter referred to as the vibration suppression operation upper limit temperature) can be set to 100 ° C. or higher. The manganese content is preferably 75% or less as an atomic ratio of the entire damping alloy from the viewpoint of castability and workability of the damping alloy.

  The manganese-based alloy contains 15 to 25% by weight of copper in addition to manganese, and further contains one or more of nickel, iron, and aluminum as needed, such as nickel 0 to 7% by weight, iron 0 to 5% by weight and aluminum in the range of 0 to 5% by weight. In the present invention, within this range, one or more of nickel, iron and aluminum may be necessarily included, or none of these may be included (each 0% by weight). . In the present invention, in such a composition, workability and mechanical properties required for the damping alloy are improved in addition to the damping function. In particular, by containing nickel and iron, the workability of the damping alloy and the stability of the damping function are improved.

The manganese-based alloy of the present invention is produced by melting and mixing a predetermined amount of raw material elements, cooling and casting. In the cooling step after the melt mixing, the average cooling rate at the time of cooling from 1150 ° C. to 900 ° C. is set in the range of 0.05 to 0.5 ° C./second. By setting the average cooling rate to 0.5 ° C./second or less, a high manganese composition part is formed inside the manganese-based alloy, and the phase transformation temperature of the manganese-based alloy is increased. On the other hand, by setting the average cooling rate to 0.05 ° C./second or more, the production cycle time of the manganese-based alloy is shortened, and efficient production becomes possible. The manganese-based alloy after casting is subjected to an aging treatment at a temperature in the range of 350 to 650 ° C. for a time in the range of 20 to 50 hours. By performing this aging treatment, it is possible to reliably set the vibration suppression operation upper limit temperature to 100 ° C. or higher.

By setting the phase transformation temperature of the manganese-based alloy to 100 ° C. or higher, the loss factor of the manganese-based alloy in a temperature environment of 100 ° C. is preferably 0.03 or higher. Here, the “loss factor” is the ratio of the storage shear modulus (G ′) to the loss shear modulus (G ″) of the manganese-based alloy, G ″ / G ′, and is usually expressed by tan δ. Shows how much energy the material absorbs when deforms.

  As for the cooling step, after that, cooling from 800 ° C. to room temperature is performed at a cooling rate slower than 45 ° C./hour or a time of 20 hours or more, so that the vibration suppression operation upper limit temperature is surely set to 100 ° C. or more. Therefore, it is preferable.

  Next, examples of the present invention will be described. Of course, the present invention is not limited to these examples.

Each of the electrolytic pure metals, manganese, copper, nickel, and iron, weighed 12 kg so that the weight ratio is Mn70.53-Cu22.35-Ni5.16-Fe1.96, placed in a magnesia crucible, and argon In a gas atmosphere, melt mixing was performed by high frequency induction heating. The melt temperature during melt mixing was controlled within the range of 1250 ° C to 1300 ° C. After the molten metal was sufficiently mixed, the molten metal was cast into a heated ceramic mold. The interior of the mold was a substantially rectangular parallelepiped, and the internal dimensions were 216 mm long, 156 mm wide, and 26 mm thick. In addition, in order to measure the temperature of the molten metal, a stainless steel sheath type thermocouple is provided in three places ((1) mold surface layer, (2) two side surfaces of the alloy ingot inside the mold (vertical side and horizontal side). On the center line connecting the center positions of the two side surfaces, a position deeper by 1/4 of the thickness of the alloy ingot from the side surface, (3) two side surfaces of the alloy ingot inside the mold (2 consisting of a vertical side and a horizontal side) On the center line connecting the center positions of the two side surfaces) to a position deep from the side surface by a half of the thickness of the alloy ingot). The data of the cooling rate is the thickness of the alloy ingot from the side surface on the center line connecting the positions of (2), that is, the center positions of the two side surfaces of the alloy ingot inside the mold (two side surfaces consisting of the vertical side and the horizontal side). It calculated using the temperature measurement value in the position of a deep part only 1/4. The temperature history in the cooling process is shown in FIG. The average cooling rate during cooling from 1150 ° C. to 900 ° C. in the cooling step was 0.1 ° C./second. As a result, a manganese-based alloy (Sample 1-0) was obtained.

  Manufacture of the manganese-based alloy was performed in the same manner as Sample 1-0 except that the mold was a water-cooled metal mold. The average cooling rate during cooling from 1150 ° C. to 900 ° C. in the cooling step was 20 ° C./second (FIG. 1). As a result, a manganese-based alloy (Sample 2-0) was obtained.

The surface of the above manganese-based alloys (Samples 1-0 and 2-0) was polished by electrolytic polishing, and the polished surface was observed with an optical microscope to evaluate the alloy structure of the cast manganese-based alloy. An observation image is shown in FIG. The local manganese composition of this tissue was analyzed with an electron probe microanalyzer, the manganese composition distribution was examined, and the heterogeneity (composition distribution) of the distribution was calculated. Here, “composition distribution” refers to the local elemental composition in a manganese-based alloy, measured by many points of the alloy with an electron probe microanalyzer (EPMA), and the weight percentage of manganese calculated from the measured value is The ratio of the number of measurement points corresponding to the weight percentage to the total number of measurement points on the axis was calculated as the half-value width of the peak curve when plotted on the vertical axis (FIG. 3). When calculated for sample 1-0 and sample 2-0, 9.65% each.
3.57%. In order to make the upper limit temperature of vibration suppression operation 100 ° C or more, the composition distribution is preferably 5% or more. From the cast manganese-based alloy ingot, the strip test is 60mm long, 10mm wide, 1mm high. The piece was cut out by machining as a test piece for evaluating the damping function. Using a DMA (solid viscoelasticity measuring device), forced vibration was applied with a vibration strain amplitude of 1.2 × 10 ⁻⁴ in the three-point bending vibration mode. The Young's modulus E (FIG. 4) was determined from the ratio between the stress amplitude and the distortion amplitude, and tan δ (FIG. 5) corresponding to the loss factor was determined as the damping function from the phase difference between the stress amplitude and the strain amplitude. Measurement conditions were as follows. The temperature was raised at a rate of 5 ° C./min in the temperature range from −100 ° C. to 200 ° C., and the vibration frequency was measured under three conditions of 0.1, 1.0, and 10 Hz.

  The alloy sample with a high average cooling rate of Sample 2-0 exhibits high vibration damping characteristics in a low temperature environment below room temperature, while the Young's modulus is about 30 GPa lower than the alloy sample with a low average cooling rate of Sample 1-0. I understood. This is thought to be due to the remarkable anisotropy of crystal growth caused by rapid solidification.

  The manganese-based alloy (Sample 1-0) was subjected to aging treatment at 400 ° C. for 2 hours after casting to obtain a manganese-based alloy sample 1-1.

  Similarly, after casting, aging treatment was performed at 400 ° C. for 5 hours, sample 1-2, 10 hours sample 1-3, 20 hours sample 1-4, 50 hours sample 1-5. It was.

  Furthermore, the manganese-based alloy (Sample 2-0) was subjected to aging treatment at 400 ° C. for 2 hours after casting to obtain a manganese-based alloy sample 2-1. Similarly, Sample 2-2 performed for 5 hours, Sample 2-3 performed for 10 hours, Sample 2-4 performed for 20 hours, and Sample 2-5 performed for 50 hours were obtained.

  Tan δ (loss factor) with respect to the temperature of each of the manganese-based alloys of Samples 1-0 to 5 and Samples 2-0 to 5 was evaluated. The data for samples 1-0 to 5 is shown in FIG. From this result, it is clear that the time of aging treatment affects the loss factor in a high temperature environment, and the loss factor is 0 in an environment of 100 ° C. (373 K) or higher by performing aging treatment for 20 to 50 hours. Since it became 0.03 or more, it was confirmed that a sufficient damping function was activated.

  On the other hand, the loss coefficient data with respect to the temperature of the manganese-based alloys of Samples 2-0 to 5 are shown in FIG. From this result, when the average cooling rate from 1150 ° C. to 900 ° C. in the casting cooling process is as fast as 20 ° C./second, the loss factor is 100 ° C. (373 K) or more even in the aging treatment. It was confirmed that 0.03 was not reached.

It is the figure which displayed the temperature history at the time of alloy manufacture of sample 1-0 and sample 2-0. It is the observation image which grind | polished the surface of the manganese base alloy manufactured by the sample 1-0 and the sample 2-0 by electropolishing, and observed the grinding | polishing surface with the optical microscope. Manganese calculated from the measured values by measuring the local elemental composition in the manganese-based alloys produced in Sample 1-0 and Sample 2-0 over many locations of the alloy with an electron probe microanalyzer (EPMA) It is the figure which plotted the ratio with respect to the total number of measurement points of the number of measurement points corresponding to the weight percentage on the vertical axis on the horizontal axis. It is the graph showing the relationship between temperature and Young's modulus of the manganese base alloy manufactured by sample 1-0 and sample 2-0. It is the graph showing the relationship between temperature and a loss coefficient of the manganese base alloy manufactured by sample 1-0 and sample 2-0. It is the graph showing the relationship between temperature and a loss coefficient of the manganese base alloy manufactured by sample 1-0. It is the graph showing the relationship between temperature and a loss factor of the manganese base alloy manufactured by sample 2-0 and 8-12.

Claims (3)

It contains 15 to 25% by weight of copper, 60% by weight or more of manganese, and one or more kinds of nickel, iron and aluminum are nickel 0 <Ni ≦ 7% by weight, iron 0 <Fe ≦ 5% by weight, aluminum 0 < In the method for producing a manganese-based alloy that contains Al ≦ 5% by weight and may contain inevitable impurities, the raw metal is melt-mixed, cooled, and cast at 1150 ° C. to 900 ° C. The average cooling rate at the time of cooling to 0 ° C. is in the range of 0.05 to 0.5 ° C./second, and an aging treatment is performed at a temperature in the range of 350 to 650 ° C. for a time in the range of 20 to 50 hours. A method for producing a manganese-based alloy characterized by the following. Manganese is contained in the range of 60 wt% or more and 70.53 wt% or less, and copper, nickel and iron are respectively copper 22.35-25 wt%, nickel 5.16-7 wt%, iron 1.96-5 In the manufacturing method of a manganese-based alloy that may be contained in the range of% by weight and may contain inevitable impurities, when the raw material metal is melt-mixed and cooled and cast, cooling from 1150 ° C. to 900 ° C. in the cooling step The average cooling rate at the time is in the range of 0.05 to 0.5 ° C./second, and an aging treatment is performed at a temperature in the range of 350 to 650 ° C. for a time in the range of 20 to 50 hours. Manufacturing method of manganese-based alloy. Manganese is contained in the range of 60 wt% or more and 70.53 wt% or less, and copper, nickel and iron are respectively copper 22.35-25 wt%, nickel 5.16-7 wt%, iron 1.96-5 In the manufacturing method of a manganese-copper-nickel-iron quaternary manganese-based alloy containing in the range of wt% and containing inevitable impurities, the raw metal is melt-mixed, cooled, and cooled when cast. The average cooling rate during cooling from 1150 ° C. to 900 ° C. in the process is in the range of 0.05 to 0.5 ° C./second, and the temperature is in the range of 350 to 650 ° C. and the time is in the range of 20 to 50 hours. A method for producing a quaternary manganese-based alloy, characterized in that: