月: 2023年3月

What Are Vibration Damping Alloys?

Vibration Damping Alloys are, as the name might suggest, alloys used to dampen vibrations in machines and structures.

Vibration can shorten the life of machinery and cause noise and discomfort. Vibration damping alloys are materials developed to solve these problems. They dampen vibration by converting mechanical energy into thermal energy. This property is used to increase the earthquake resistance of large structures such as buildings and bridges.

They are also used in vibration-sensitive products such as precision equipment and audio equipment.

Uses of Vibration Damping Alloys

1. Construction

Vibration damping alloys are sometimes incorporated into steel or concrete structures to absorb and dampen vibration during earthquakes. They are also used in the design of highway bridges to improve safety against major earthquakes, typhoons, and other disasters. Examples include buildings, bridges, and highways.

2. Earthquake Protection

Vibration control devices built into buildings absorb and dampen the shaking that occurs during earthquakes, thereby reducing damage to buildings. This is especially used in high-rise buildings.

3. Vibration Control

Vibration damping devices are sometimes used in vehicle suspensions, as well as around the hulls and engines of ships. They absorb vibration caused by high-speed driving, improve riding comfort, and protect equipment.

In addition to vehicles, ships, and other forms of transportation, they are sometimes used for vibration control of large machinery and equipment at factories and construction sites. They prevent breakdowns and deterioration of machinery caused by vibration, thereby improving productivity and extending the life of equipment.

4. Vibration Countermeasures for Medical Equipment

Vibration countermeasures are sometimes used for high-precision medical equipment such as MRI and ultrasound diagnostic equipment. It reduces vibration of precision mechanical parts and sensors inside the equipment to improve the accuracy of diagnostic results and extend the life of the equipment.

5. Vibration Control for Furniture and Home Appliances

Vibration control is sometimes used in home appliances such as washing machines, refrigerators, and air purifiers, and in furniture such as the legs of tables and desks, and the frames of sofas.
In home appliances, they are used to reduce noise caused by vibration and to prevent breakdowns over long periods of use.

Types of Vibration Damping Alloys

1. Composite Vibration Damping Alloy

Composite vibration damping alloys are a combination of several metals or alloys. Typically, this type of alloy includes high-strength steels, stainless steels, titanium alloys, aluminum alloys, and copper alloys. Combining the properties of these metals and alloys can achieve high vibration damping alloy performance and excellent durability.

They have different properties depending on their composition and manufacturing method, but in general they are characterized by high vibration damping performance, durability, wear resistance, heat resistance, corrosion resistance, and low density.

2. Ferromagnetic Vibration Damping Alloys

Ferromagnetic vibration damping alloys are capable of controlling vibration using a magnetic field and are characterized by high vibration damping performance. Alloys of this type generally include ferritic steels and permalloys. They can store magnetic energy, and when vibrations occur, they can release magnetic energy to dampen vibrations.

3. Shifting Vibration Damping Alloys

Vibration damping alloys of the shifting type are capable of controlling vibration through phase transitions, and are characterized by high vibration damping performance over a wide temperature range.

Alloys of this type generally include nitinol and martensitic steels. Because of the property that the modulus of elasticity changes significantly as the crystal structure changes over a specific temperature range, these alloys are used for vibration control in environments with large temperature fluctuations.

4. Twin-Crystal Type Vibration Damping Alloy

Vibration damping alloys of the twin-crystal type have a special structure at the grain boundary, which enables them to exhibit high vibration damping performance. They generally include copper alloys and aluminum alloys. The tiny crystal structures called twin crystals at the crystal grain boundaries absorb and dissipate vibration energy, thereby damping vibration.

They are characterized by their special crystal structure, which enables them to exhibit stable vibration damping performance even in high-temperature environments. They also have excellent corrosion resistance, making them suitable for use in marine environments.

Principle of Vibration Damping Alloys

Vibration damping alloys are materials that have a higher ability to absorb vibration than ordinary metals. The mechanism by which they absorb vibration lies in the microstructural structure inside the material. Generally, the material is composed of two or more different metals. Thus, the different metals are stacked in microscopic layers and bonded to each other to form a single unit.

When vibrations are transmitted to vibration damping alloys, the friction between the different metal layers absorbs the vibrations and the energy is dissipated internally, allowing vibration damping alloys to absorb the vibrations effectively. In addition, the vibration modes inside the material change according to the vibration frequency, allowing effective vibration absorption over a wide range of vibration frequencies.

Vibration mode refers to the form of vibration that an object can take when it vibrates. Specifically, when an object vibrates, the vibration contains waves of various frequencies, and the vibration mode differs depending on how each frequency component vibrates inside the object.

Vibration damping alloys are materials that absorb vibration by means of a microscopic layered structure and dissipates the energy internally.

Properties of Vibration Damping Alloys

1. Vibration Damping

Vibration damping alloys are used to dampen vibration caused by earthquakes in buildings and structures due to their high ability to absorb vibration. Vibration is absorbed by friction between different metal layers and by structural changes within the material, so they can effectively absorb vibration over a wide range of frequencies. For example, vibration control devices used for earthquake countermeasures for buildings are designed to match the frequency band of earthquakes.

2. Durability

Vibration damping alloys are characterized by their durability and ability to maintain performance over a long period of time because the metal layers are tightly adhered to each other. For example, they are used in railroad vehicles. Since they are composed of several different metals, they have excellent properties as metallic materials.

Other Information on Vibration Damping Alloys

1. Wide Range of Applications

Vibration damping alloys are used in a wide variety of applications, such as seismic and acoustic vibration damping alloys, due to their vibration absorption ability and durability. For example, they are used for earthquake countermeasures, sway control of high-rise buildings, soundproofing of acoustic studios, vibration control of ships and airplanes, and vibration reduction of precision machinery.

2. Materials Other Than Vibration Damping Alloys

In addition to vibration damping alloys, there are various other vibration-damping materials such as rubber, urethane foam, silicon rubber, resin, and ceramics. These materials are lighter than vibration damping alloys and their damping performance varies depending on the vibration frequency.

What Is Red Brass?

Red brass, an alloy of zinc and copper, has a lower zinc content than regular brass. Typically, red brass refers to alloys with a zinc content ranging from 3% to 20%, characterized by their reddish color and softness. Alloys with about 10% zinc are known as red brass, while those with around 15% zinc are referred to as gold brass.

The color of the alloy becomes more reddish, termed “red-copper color,” as the zinc content decreases. At approximately 10% zinc, the color shifts to yellowish-red, and at around 20% zinc, it takes on a light orange hue.

Uses of Red Brass

Softer and more malleable than standard brass, red brass is commonly used in building materials, ornaments, and jewelry, leveraging its distinctive reddish appearance. Its color varies with the zinc content.

Red brass is also popular in brass bands and other brass instruments. This preference is not just due to its aesthetically pleasing color but also because of its corrosion resistance, workability, and sound retention qualities.

Characteristics of Red Brass

Red brass shares basic properties with brass, including good tensile strength, ductility, and electrical conductivity. It is more resistant to rust compared to steel. However, due to its lower zinc content, red brass is softer and less suited for applications that require hardness. It offers superior ductility and drawability compared to regular brass.

An important feature of red brass is its light red color, attributed to its higher copper content, making it similar in appearance to copper. This quality makes it a favored choice for ornamental uses. While red brass has a certain level of corrosion resistance, it can oxidize and form bluish-green verdigris, similar to pure copper, when exposed to oxygen. Therefore, despite its aesthetic appeal, it requires more maintenance than compared to highly corrosion-resistant materials like stainless steel.

What Is Rimmed Steel?

Rimmed steel is a type of steel that undergoes minimal or no deoxidization during the ingot formation process. In contrast, steel ingots that are fully deoxidized are referred to as kiln-dried steel.

Rimmed steel, being insufficiently deoxidized, generates bubbles during the casting and solidification of the ingot. These bubbles form a tubular layer within the outer shell of the ingot, known as the rim layer. Originating from CO gas, these bubbles do not lead to defects in the steel as they collapse during the hot rolling process.

Uses of Rimmed Steel

Rimmed steel, due to its lack of deoxidization and the absence of oxygen scavengers, offers a high yield at a relatively low cost. However, its minimal deoxidization leads to significant internal segregation and inconsistent quality, marked by varying levels of impurities like carbon and phosphorus. This inconsistency makes rimmed steel less suitable for machine parts requiring high reliability. It is typically used for products where segregation is not a concern, such as wire rods, plates, bolts, nuts, and tin plates.

Characteristics of Rimmed Steel

Rimmed steel, characterized by its high dissolved oxygen content, releases sparks and gases during casting and solidification. This process forms a rimmed layer at the periphery, with a tubular bubble layer inside, leading to significant segregation. The quality of the steel varies greatly between the periphery, which is closer to pure iron, and the interior, which contains higher levels of impurities like phosphorus and carbon. When cut, the tubular bubbles in rimmed steel may manifest as surface imperfections, making it unsuitable for applications demanding high reliability.

Despite these characteristics, rimmed steel offers cost advantages due to the minimal use of oxygen absorbers and a high yield rate, with no cavities or shrinkage as seen in kiln-dried steels. The surface, being composed of pure iron, has good paint adherence, making rimmed steel suitable for applications like rolled steel where surface quality is a priority.

What Is a Pink Noise?

Pink noises are noises whose power density is inversely proportional to their frequency.

It is called pink noise because light with the same frequency component appears pink. It is characterized by a “zing” sound, like the sound of strong rain or a waterfall. Pink noises have a constant energy per octave band and are used as a signal source for various acoustic measurements.

A similar type of pink noise is white noise, which has a constant power regardless of its frequency. It is considered to have a calming effect because it sounds pleasant to the ear. Pink noises are also called “1/f Fluctuations” because their power is inversely proportional to their frequency, and in nature, they are sometimes compared to the tides on a sandy beach.

Uses of Pink Noises

Pink noises are used as a signal source over a wide frequency range for testing audio products such as amplifiers, speakers, and headphones, as a signal source for testing electronic equipment, and as a sound source for human hearing tests and healing.

Principle of Pink Noises

Pink noises are also called 1/f Noises because their power is inversely proportional to their frequency. Here, f is the frequency. The general expression for noise broadly speaking is S(f)∝1/f^α.

Note that S(f) is the spectral density, f is the frequency, and α is 0=<α<=2. For pink noises, α is around 1. In this case, the spectral density is attenuated by a factor of 10 in frequency, α x 10dB.

Noise with α around 1 is found in nature, including tidal noise, and has been the subject of much research. Also, α = 0 is white noise, and α = 2 is called red noise.

Other Information on Pink Noises

1. Effects of Pink Noises

Pink noises are often used for testing audio products and electronic equipment. Another important use is as a sound source. Because of its high low-frequency content, pink noises, when heard by the ear, have a soothing effect by blocking out external sounds. It is also a pleasant sound because it is close to natural noises that humans can easily hear.

Therefore, it is used in some cases as an environmental sound to improve concentration and productivity. Another benefit of pink noises is its positive effect on sleep. It is said that the brain converts short-term memories into long-term memories during sleep.

Among non-REM sleep, slow-wave sleep, a particularly deep state of sleep, is necessary for long-term memory. Research has shown that acoustic stimulation with pink noises during slow-wave sleep improves memory.

2. How to Create Pink Noises

Pink noises can be easily created by using a noise generator, by using an electronic circuit such as a diode, or by using a programming language.

Noise generators include those used in electromagnetic interference EMI tests and acoustic characteristic tests, as well as those built into function generators. The noise generator can generate white noise, pink noises, etc., by selecting the desired type of noise. Noise generators attached to synthesizers can also be used.

To use a noise generator circuit with a zener diode, transistor, or operational amplifier, first create white noise. Then, a power attenuation inversely proportional to the frequency is applied to make pink noises. Power attenuation requires -3 dB/oct, so a circuit called a lag-lead filter is used.

Another method is to use a programming language such as C, Java, or Python. Noise is generated in software using random numbers.

3. Color Representation of Noise

It is common to represent noise in terms of color. These are called “colored noise,” and include white, pink, red, brown, blue, violet, purple, and gray. Noise is determined by its frequency components, and noise is represented by the color of light having the same frequency components.

White noise contains all frequencies uniformly and is perceived as a “sough, sough” like the sound of a ⾵ sound or the sound of a low river. Red noise is a noise with a power density that decreases by 6 dB per octave of frequency. Pink noises are between white and red, with a power density of 3dB lower per octave of frequency. It sounds like a “zing,” like the sound of rain or a waterfall.

Blue noise is also a noise whose power density increases by 3 dB per octave with increasing frequency. It has a limited frequency range. Purple noise is noise whose power density increases by 6 dB per octave. It has a finite frequency range and is equal to the derivative of white noise.

Gray noise is noise with a power density close to the auditory equal loudness curve. The equal loudness curve is an equal-hearing curve with a large attenuation of power density around 2,000 Hz and a smaller attenuation at lower and higher frequencies.

What Is C11000 Copper?

C11000 Copper is a copper alloy with a copper content of 99.90% or more. It has high electrical conductivity and excellent thermal conductivity.

C11000 Copper is also used in various fields such as electrical wiring, machine parts, and construction materials because of its light specific gravity and high corrosion resistance. Furthermore, it has excellent workability and can be processed into various shapes, such as plates, rods, and tubes.

It is one of the most widely used copper alloys with excellent performance for a variety of applications.

Uses of C11000 Copper

The main applications of C11000 copper are as follows:

1. Electrical and Electronic Components

C11000 Copper is widely used in the manufacture of electrical and electronic components due to its high electrical conductivity and plasticity. Examples include coils, transformers, connectors, wiring, and printed circuit boards.

A transformer is an electrical component that uses the principle of electromagnetic induction to convert voltage or current. A printed circuit board (PCB) is a board-shaped component that serves as the base for an electric circuit. Generally, a printed circuit board (PCB) is made of glass fiber reinforced resin or polyimide resin, on which a thin layer of copper foil is attached and on which conductive patterns are printed. 

2. Building Materials

C11000 Copper is also used as a building material because of its beauty and durability. Examples include doorknobs, railings, sinks, bathtubs, and ceiling and wall decorations.

3. Thermal Conductive Material

Due to their high thermal conductivity, they are used as thermally conductive materials. Examples include heat exchangers, heat sinks, and coolers.

4. Other Applications

Automotive parts, ship parts, processing machinery, medical equipment, etc.

Properties of C11000 Copper

The main properties of C11000 copper are as follows:

1.Conductivity

C11000 Copper is highly conductive because copper itself is an excellent electrical conductor. Copper is one of the metals with very low electrical resistivity and has the highest electrical conductivity among metals.

C11000 Copper is an alloy based on high-purity copper, which allows the high electrical conductivity of copper itself to be enhanced. Tough pitch copper also has fine crystalline particles, which have fewer gaps that obstruct the movement of electrons between crystalline particles, resulting in higher conductivity. In addition, heat treatment makes it possible to form the crystal particles uniformly, which improves conductivity. Heat treatment makes fine crystalline particles exist in close proximity to each other, which prevents the movement of electrons, resulting in higher conductivity. 

2. Processability

C11000 Copper is easy to work because of the uniform distribution of fine crystal particles and good malleability and ductility. Its low strength and high plasticity also make it easy to deform and hold its shape, and its high thermal conductivity allows the heat generated during processing to escape evenly and suppresses temperature rise.

Malleability is the property of a metal that is easily deformed by forging, rolling, or other forces when it is processed. Ductility is the tendency of a metal to be deformed by being pulled or stretched. Plasticity is the property of a metal that allows it to deform and maintain a new shape under pressure or force. In other words, it is the ability of a metal to maintain its new shape without retaining its original shape when deformed. 

3. Corrosion Resistance

C11000 Copper is an alloy based on high-purity copper, which has its own corrosion resistance. Copper is generally stable against many oxides and hydroxides, and furthermore, the oxide film formed on the copper surface makes it a corrosion resistant material. In addition, the fine and uniform crystalline particles stabilize the microstructure within the material and enhance its corrosion resistance. Special heat treatment keeps the crystal particles uniform, so corrosion resistance increases after heat treatment. 

4.Thermal Conductivity

C11000 Copper is a material with high thermal conductivity due to its fine and uniform crystal particles. In addition, copper itself is a good thermal conductor, which also makes C11000 copper a good thermal conductor. Copper itself is an efficient conductor of heat. Copper atoms are densely packed, so the distance between atoms is short and heat energy is easily transferred.

C11000 Copper is an alloy based on high-purity copper, and in addition to the thermal conductivity of the copper itself, special manufacturing methods are used to form fine crystal particles. Therefore, heat conduction inside the material is smooth, resulting in high thermal conduction performance. In addition, the high uniformity of the crystal particles ensures uniform heat transfer, resulting in high heat conduction throughout the material.

5. Excellent Corrosion Resistance

C11000 Copper is an alloy based on high-purity copper, a material with excellent corrosion resistance. In addition, special heat treatment gives it a uniform crystalline particle structure, further enhancing its corrosion resistance. In addition, C11000 copper has antibacterial properties against microorganisms, making it an excellent material for corrosion resistance. 

6. Antimicrobial Properties

C11000 Copper has the same antimicrobial properties as other copper materials. Copper has excellent antimicrobial properties and is known to kill many types of bacteria, viruses, and other microorganisms. The antimicrobial properties are attributed to the ions present on the surface of copper.

C11000 Copper also has high purity and uniform crystalline particles, resulting in high antimicrobial performance. The surface of C11000 copper also tends to release copper ions that can damage cell membranes and enzymes. This makes it suitable for applications requiring antimicrobial properties in fields such as medical devices and food processing equipment.

Other Information on C11000 Copper

Alternatives to C11000 Copper

Alternatives to C11000 copper include copper-nickel alloys and silver-plated copper. These materials also have high electrical conductivity and corrosion resistance, but their properties, such as workability and thermal conductivity, differ from those of C11000 copper, making C11000 copper more suitable for some applications.

What Is Annealing?

Annealing, also known as “diffusion annealing,” is a type of heat treatment that diffuses and homogenizes segregated elements created in a steel ingot during steelmaking.

In the molten state, heterogeneity between the surface and the interior, especially the center, of a steel ingot is inevitable, but homogenization improves the quality of the product. Annealing is generally performed for a long time in the austenitic temperature range, which is a high temperature range.

The austenite temperature range refers to the temperature range where austenite, one of the four types of carbon iron, becomes austenite.

Uses of Annealing

Annealing is used to homogenize the inhomogeneities that occur during the steelmaking process of high-alloy steels (e.g., tool steels).

There are several different annealing methods, such as “full annealing,” “spheroidizing annealing,” “isothermal annealing,” and “stress relief annealing,” each used for different purposes. The lowest temperature is for stress-relief annealing, at about 700°F.

Other Information on Annealing

Characteristics of Annealing

Starting with the highest annealing temperature of just under 1,800°F, annealing temperatures progressively decrease to “isothermal transformation annealing,” “complete annealing,” “spheroidizing annealing,” and “stress-relieving annealing.”

The purpose of different annealing methods varies; for example, isothermal transformation annealing improves machinability, complete annealing homogenizes the structure by aligning the grain size, spheroidizing annealing improves workability, and stress relief annealing prevents cracking during use by removing residual stress.

The effects of annealing vary depending on the material. Free-cutting steel prevents red hot brittleness, bearing steel removes carbide segregation, tool steel improves machinability and extends service life, stainless steel improves corrosion resistance, and heat-resistant steel improves creep strength.

Heat treatments include “quenching,” “tempering,” and “normalizing,” each with a specific purpose: quenching increases hardness, tempering after quenching improves tenacity, and normalizing reduces micro-structural irregularities and improves impact resistance.

What Is a Skin Pass Rolling?

A skin pass rolling is one of the processing methods used to process metal materials such as steel sheets.

The purpose is to correct the distortion caused by cold rolling and to smooth the surface of the sheet material to make the surface shiny. Since skin pass rollings may reduce the strength of the sheet, heat treatment may be applied after skin passings to reinforce the strength of the sheet. Skin pass rollings are widely used in the processing of steel plates and other metal materials.

Uses of Skin Pass Rollings

1. Building and Construction

Exterior wall and roofing materials, treads and frame parts for elevators and escalators, and steel structural parts for water supply facilities and river bridges are examples.

2. Automobiles and Transportation Equipment

Automobile exterior panels and frame parts, railroad car exterior panels and frame parts, ship exterior panels and structural parts, etc.

3. Home Appliances and Electronics

Housings and frame parts for home appliances, housings, and frame parts for medical equipment, housings and frame parts for vending machines and ATMs, housings and frame parts for machine tools and measuring instruments, etc.

4. Others

Enclosures and frame parts for lighting fixtures and ceiling fans, and frame parts for golf clubs and tennis rackets are examples.

Properties of Skin Pass Rollings

Skin pass rolling is a light rolling process to smooth the surface of a sheet material, which corrects the distortion of the material and evens out the unevenness of the surface, resulting in even light reflection and luster. Flatness and surface hardness can also be improved.

Skin pass rollings are used as a final finish before more precise processing because they are simple, light rolling or drawing, and do not cause significant deformation of the material after processing.

Types of Skin Pass Rollings

There are three main types of skin pass rollings. The names may differ.

1. Skin Pass Rollings for Cut Plates

Skin rollings are used to adjust the surface condition and correct rolling distortion. The material is processed while light pressure is applied to correct the distortion of the material. The pressure is adjusted according to the strength and hardness of the sheet.

Skin pass rollings for cut sheets are less productive and time-consuming because the sheets are processed one at a time, but it is highly flexible because the sheets to be processed are small and can be formed into a variety of shapes. It is also often used as a final finish before precision machining, since the surface of the plate after machining is smooth and flat.

2. Continuous Skin Pass Rollings

Continuous skin pass rolling is one method to continuously process metal materials. A large amount of sheet metal in coil form can be processed at once in a short time, and as the coiled sheet material passes through the skinpass mill, the surface condition of the sheet material is adjusted and distortions are corrected.

Continuous skin pass rollings are a processing method suitable for high-volume production, and their high productivity reduces processing costs. The high processing speed allows for the processing of a large number of sheets in a short time. The processing force can be adjusted according to the thickness of the sheet material, making it possible to process a wide variety of metal materials.

3. Tension Leveling

Tension leveling is a type of skin pass rolling, which is a process of removing surface irregularities by applying tension to the steel sheet and utilizing the reaction of the tension to make the surface flat.

Tension levelers are processing machines that correct rolling distortion and remove warpage by repeatedly bending coiled plates. Tension levelers use the tension (tensile force) inside the coil to bend the sheet material and process it in a bent state.

It is more precise than skinpass mills and can effectively remove rolling distortion. In addition, the repeated bending of the plate material allows the surface irregularities to be evened out, which is a characteristic feature of this process. It is also effective in improving the hardness of plates and is one of the indispensable processing machines for manufacturing high-quality plates.

There are two types of tension levelers: roller levelers with rolls at the front and rear, and top and bottom levelers with rolls at the top and bottom. The former corrects rolling distortion while moving the plate back and forth, while the latter corrects rolling distortion while moving the plate up and down. It is important to select the appropriate tension leveler according to the shape of the sheet material to be used and the purpose of processing.

Other Information on Skin Pass Rollings

Skin Pass Rollings for Plastics

Skin pass rollings are a processing technique mainly used for processing metal materials but are also sometimes used for processing plastic materials. In the case of plastic materials, Skin pass rollings on transparent plastic materials, such as polycarbonate and acrylic resins, can be used to even out surface irregularities and produce a beautiful finish.

Skin pass rollings make the surface of transparent plastic materials uniform and beautifully finished. Small scratches and flaws on the surface of the plastic material can also be polished away in the process.