User:細谷武司

= M2052 Dmaping alloy =

M2052 is composed of manganese 73, copper 20, nickel 5, iron 2 (atomic weight%) and has high vibration damping performance Manganese alloy. Under the vibration load, twinning activity (occurrence, disappearance, movement) occurs in the alloy, whereby vibration energy is converted into thermal energy and exerts vibration damping properties. It has tensile breaking strength similar to that of mild steel, most molding processes such as machining starting from plastic working are possible, and the larger the amplitude within the elastic limit The vibration damping performance shows a high value.

Characteristic
As mentioned above, M2052 is characterized by high vibration damping performance which shows high value with larger amplitude within elastic limit and versatility which comes from free shape designability, so it is natural that M2052 Various correspondence can be expected.

For example, in addition to countermeasures against floor vibrations, internal vibrations, chattering, damping and vibration isolation in industrial machinery and machine tools, measures to prevent Hakuro disease by chainsaw and shock buffering of air hammers, crushing machines at construction sites Electromagnetic induction noise caused by vibration in audio, measuring instruments, and electronic equipment as well as noise reduction, noise reduction and sound insulation measures against noises countermeasures, expected responses such as sound insulation of silent sound of cars, ships, walls and ducts of buildings, noise reduction, noise reduction, etc. are diverse. Moreover, it can respond to new vibration problems such as rolling shutter phenomenon of camera image with drone. The features of M2052, etc., are effective elements for countermeasures against vibration problems in various fields.

history
The M2052 damping alloy has a damping mechanism called a crystal twinning type and has a property of extremely easy movement of the transformation twin boundary seen in the thermoelastic martensitic transformation, so it exhibits a large damping capacity. Sonostone, the same twinning type, was invented about 70 years ago and is still alive in military-related vessels.

M2052 Damping alloy was invented and patented during research of Mn alloy from 1988 to 1995 at the National Institute for Materials Science and Technology.

After that, in 1998, application to audio accessories began as the Black Metal and utilization of processability was utilized Insulator,  Screws,  Washers, Powder, Sheet material Has been developed.

Application examples first appeared in the industry are machine tool mounts announced by Seisin Engineering Co., Ltd. and packing for flanges of grinding wheels.

However, the M2052 damping alloy is easy to use and can design a free shape, but it can not be said that it is still popular. There are issues related to the cooperation of the manufacturing organization of materials and the proposed organization of applications (usage), and issues relating to the elimination of the cost increase due to small volume production. Although there is a recent raw material price, it is urgent to propose an application that can balance the supply demand with the total demand and to lower the price.

Recipe
M2052 damping alloy is melted in the crucible at the raw material ratio of Mn 73, Cu 20, Ni 5, Fe 2 (atomic weight%) and alloyed. Dissolution is carried out in a vacuum induction furnace filled with argon gas and becomes an ingot.

Next, billets are made by forging and processed into raw materials such as round bars and plate materials.

In the dissolution process, it is important to manage O, N, S and C, and contamination from crucible and the purity of raw materials Mn, Cu, Ni, Fe, etc. It is a management point.

Classification of damping alloys
Damping alloys are classified into four types from (1) composite type (2) ferromagnetic type (3) transfer type (4) twin crystal type from the viewpoint of damping mechanism.

What has long been known as a structural member with damping properties is a composite cast iron, and is still active as a mother body and base of machine tools.

Ferromagnetic type silentaraye (Fe - 12Cr - 3Al, Toshiba) and Selena (Fe - 2.4 Al - 0.54 Si, NKK) are well known.

Transfer type magnesium alloy is lightweight.

Sinostone (Mn-37Cu-4.25Al-3Fe-1.5Ni, Manganese Marine Co.) is used as a screw for military vessels for sonar measures in the twin crystal type. Many of the twin crystal damping alloys represented by Sonostone are well known alloys of Mn and Cu. The amplitude dependence is linear, and the vibration damping performance is proportional to the amplitude, but the method of molding processing is limited and it is used as a casting.

M2052 vibration damping alloy belongs to twin crystal type, vibration damping performance is proportional to the amplitude, parts can be manufactured by many processing methods while having characteristics.

Characteristics of M2052 damping alloy
M2052 damping alloy has the following characteristics.


 * 1) Damping characteristics correspond to wide stress, frequency and temperature. In the elastic region, the higher the amplitude, the higher the vibration damping property is. The frequency can absorb vibration from <0: 01 Hz to 5 MHz. The use temperature is wide, from 4.2 to 375 K.
 * 2) The strength is about mild steel and functions as a structural member.
 * 3) Excellent molding processability, product shape and size can be freely selected.
 * 4) Vibration damping performance has mass production performance of 0.2 ~ 0.3 in logarithmic decay rate.
 * 5) Damping properties are maintained even at helium liquefaction temperature, and ductility is not lost.

mechanical nature
M2052 has the following mechanical properties.

Allowable stress：


 * Tensile strength 540 MPa (compression)
 * Longitudinal elastic modulus (3 point bending) 67.7 GPa
 * Transverse modulus (Tension) 17.8 GPa
 * Poisson ratio (tension) 0.338
 * Elastic limit (tension) 300 MPa
 * Strength 0.2% (tension) 205 MPa
 * Fatigue limit [Bending] (Stress) 160 MPa Distortion 5 × 10 5
 * Hardness Hv 100 to 130
 * Linear expansion coefficient (300 K) 22.4 × 10 - 6 / deg
 * Specific heat (300 K) 512.7 J / Kg · K
 * Thermal conductivity (300 K) 10 W / m · K
 * Magnetic paramagnetic / antiferromagnetic
 * Density 7.25 gr / cm 3

Amplitude dependence
Twin crystal vibration damping alloys have characteristics that the number of occurrences of twinning and movement increases as the amplitude increases, and the vibration absorption capacity increases due to the crystal twinning activity.

Frequency dependence
The vibration damping performance by the frequency band has not consistently measured data from 0.01 Hz to ultrasonic range. Reference [1] described by the inventor is a measurement result based on the frequency sweeping method performed in the range of 75 Hz to 4.3 kHz but, the lower the frequency, the smaller the attenuation characteristics. Also, even in the high frequency range of 3 to 5 MHz in the ultrasonic range, a logarithmic attenuation factor of 0.7 or more was obtained, which is similar to rubber.

Temperature dependence
The vibration damping performance of the standard composition M2052 damping alloy deteriorates in the high temperature range with the limit of 80 ℃.

Further, researches are under way to shift the critical temperature to a high temperature by increasing or decreasing the composition of Mn, Cu, Ni and Fe.

Processability
M2052 Damping alloy can be molded in various forms.

It is possible to perform casting, welding, rolling, cold forging, wire drawing, powder production, machining (cutting, grinding, etc.) press working which is a molding process for obtaining a shape necessary for application.

Usage and application example
M2052 vibration damping alloy absorbs vibration energy by receiving vibration stress directly. Therefore, there is a method of directly sandwiching it in the vibration transmission path (serial insertion) and a method of placing it as a damper in the vibration transmission path (parallel insertion). In parallel insertion, there is also a method of adding a function of a composite vibration damping material such as a vibration damping steel plate by pasting a sheet material on the surface of the metal plate.

It can be said that M2052 which can produce free shapes, has simple amplitude dependence, can be applied to a wide range. However, it can not absorb large energy like an earthquake, and it is not adopted in the field where sufficient measures can be taken with rubber or resin.

M2052 Damping alloy began to be applied in the field of acoustic equipment and imaging equipment, and gradually spread to the field of countermeasures against bubbling of machining machines and improvement of surface roughness.

External link

 * M2052 laboratory　-　Homepage of the research institute that has been involved from application to manufacturing method for 20 years from the dawn of M2052

   