Machinable Glass Ceramic

Machinable ceramics are a type of polycrystalline composite phase material, which is a glass-ceramic with synthetic mica crystallites as the principal crystal phase. Machinable glass ceramics, commonly known as Macor, are a multifunctional material that combines the features of glass and ceramics. They are white in color and have a dense structure. They are designed specifically for easy machining, enabling accurate shaping and customization.

Tags Machinable Glass Ceramic

Introduction

Application

Material Properties

Machinable glass ceramics are mostly comprised of a mixture of glass and ceramic powder, which are fluorphlogopite glass-ceramics with synthetic mica as the main crystal phase. They are composed of fluorphlogopite (Mg3K[AlF2O(SiO3)3]), and glass that mainly consists of silica. The following are the benefits of machinable glass ceramics:

Machinability

Excellent machinability is one of the key benefits of machinable glass ceramics. It can be easily processed using standard processing methods like milling, drilling, grinding and turning, and intricate geometrical shapes, complicated patterns, and accurate dimensions, such as varied ceramic thin walls, ceramic threads, etc., and also be processed without the need for opening the mold. There is a significant reduction in the design and processing cycle, and no specialized tools or equipment are needed.

Thermal Stability

Machinable glass ceramics provide great thermal stability. They have a low coefficient of thermal expansion, therefore can endure fast temperature fluctuations from minus 200 degrees to 800 degrees without breaking or cracking. As a result, they are frequently used in welding fixtures and molding molds for optical glass.

Electrical Insulation

Machinable glass ceramics offer superior electrical insulation properties (electric breakdown up to 40KV/A per mm), high resistance, and low dielectric loss, making them appropriate for electrical insulation-required applications. For example, they can be used as electrical insulators in electrical systems, connectors, and components, etc.

Corrosion Resistance

Because of their outstanding chemical resistance, machinable glass ceramics can withstand environments containing a variety of chemicals and corrosive substances. They are resistant to most solvents, acids, and alkalis, which makes them used in various chemical equipment. They are more corrosion-resistant, not aging, and have a long service life when compared to PTFE.

Low Vacuum Outgassing Rate

Machinable glass ceramics have exceptionally low vacuum outgassing rate (thus they are extensively employed in various vacuum equipment, photovoltaic vacuum coating equipment, and so forth). On the other hand, they also possess outstanding electromagnetic performance, having been used on a large scale as various coil skeletons.

UNIPRETEC can provide you with various specifications of blank materials in stock (bars, plates, blocks, etc.). The available machinable ceramic rods have the following specifications:

Customers can directly purchase the blank materials and process them into needed ceramic parts using existing equipment like processing metals. Additionally, UNIPRETEC offers processing services according to the drawings provided. Our company is equipped with a number of CNC lathes, surface grinders, and machining centers, and the delivery cycle is short.

Applications

Because they are so versatile, machinable glass ceramics find use in many different sectors. They find use in the aircraft industry for structural components, sensors, and insulators where dependability and accuracy are essential. Their outstanding dielectric characteristics are used in electronics as substrates for circuits and components for high-frequency devices.

Additionally benefited by these materials are medical gadgets. Their chemical inertness and biocompatibility find use in implants, surgical instruments, and diagnostic equipment. Labs employ machinable glass ceramics for equipment like reaction containers and crucibles where chemical and high temperature resistance is crucial.

Benefits

Selecting UNIPRETEC machinable glass ceramics has several advantages. Their simplicity of machining makes it possible to create accurate and complicated pieces with design freedom. Product development cycles are accelerated by this and the reduced production costs and quick prototyping.

Furthermore preserving their outstanding performance, our materials provide long-term dependability in severe applications. For cutting edge technical domains, their combination of chemical resistance, electrical insulation, and thermal stability makes them a great option.

Innovation dedication

Our commitment at UNIPRETEC is to ongoing innovation and development. Our goals are to increase the capabilities and broaden the uses of our machinable glass ceramics. Modern solutions catered to the particular requirements of our customers are guaranteed by our commitment to quality and performance.

Ultimately, UNIPRETEC machinable glass ceramics provide unmatched performance and adaptability. For the most exacting uses in aircraft, electronics, medical equipment, or laboratory equipment, our materials provide the dependability and accuracy needed. With our cutting edge goods, we look forward to assisting you in reaching your objectives.

Because of their superior machinability, vacuum property, electrical insulation, thermal shock resistance, and chemical corrosion resistance, machinable ceramics are widely employed in a wide range of industries and applications.

Insulating Parts

Because of their machinability, machinable ceramics can be made into a range of structural ceramic parts with complex structures, including insulating pads, heat insulating pads, insulating supports, and heat-resistant supports for different mechanical equipment.

Key Parts of Lightning Rod

Machinable ceramics offer exceptional high-temperature electrical insulating properties and can be employed in a variety of electrical equipment like lightning rod essential parts.

Welding Fixtures and Optical Glass Overmolding Molds

Machinable ceramics can be used in temperatures between -200°C and +800°C. Due to the elasticity of the mica crystals in glass-ceramics, they can prevent the extension of microcracks, resulting in excellent thermal shock resistance. For hermetic bonding, their low coefficient of thermal expansion guarantees dimensionally stable workpieces. Their common applications include welding fixtures and optical glass overmolding molds.

Vacuum Equipment Supports

After baking at 180°C for 1 hour, holding at 160°C for 1 hour, and vacuum ageing for 8 hours, the machinable ceramics offer exceptionally low outgassing rate of only 8.8x10-9 ml/s. cm2, making them widely employed as supports in vacuum chambers of various vacuum equipment, such as vacuum equipment supports, photovoltaic industry vacuum coating supports.

Chemical Industry Components

Machinable ceramics have good corrosion resistance. Since they are entirely made of inorganic materials, they also possess properties of never ages or deforms, are extremely stable to a wide range of organic solvents, and excellent resistance to acid and alkali corrosion. As a result, they are utilized in the chemical industry as varying essential components, such as the electrode introduction rod for crude oil desalting, hanging.

Missile Gyroscope Coil Skeletons

Machinable ceramics can be made into coil skeletons of missile gyroscopes because they have outstanding electromagnetic characteristics.

Rotary Vacuum Pump Vanes

When there are no metal particles present, machinable ceramics behave like graphite and are exceptionally self-lubricating. They are lighter than aluminium, have a specific gravity that is just one-third that of ordinary steel, and possess a very low water absorption rate. As a result, they are typically used as rotary vacuum pump vanes.

All in all, superior comprehensive characteristics of machinable ceramics enable them to satisfy high-precision technical requirements without the necessity for mold design and manufacture, drastically reducing the development cycle, accelerating engineering advancement, and lowering development costs. Consequently, they gain great popularity in extensive research, teaching and design departments. They are particularly well suited for widespread usage in autos, the military, aerospace, precision instruments, medical equipment, electric vacuum devices, electron beam exposure machines, textile machinery, sensors, mass spectrometers, and energy spectrometers, etc.

Machinable ceramics are polycrystalline composites with exceptional machinability that can be processed into elaborate geometries, intricate patterns, and precise dimensions. They are superior electrical insulators and have low thermal expansion coefficient, good thermal stability, high breakdown strength, and low dielectric loss. Additionally, they can withstand harsh chemical environments thanks to their high corrosion resistance. They are resistant to ageing and have a long service life.

Processing of Machinable Ceramics

Machinable ceramics is a new type of ceramic material that can be processed into products with precise tolerances using the commonly used metal processing tools and devices. Their processing techniques are briefly described as follows:

Turning

The key to turning is to use a low cutting speed, preferably greater than 100 rpm, because the lower speed can cool the workpiece, preventing the formation of small cracks on the ceramic surface. The cutting speed is 0.05-0.13mm/r. Once proficient, cutting 3 mm at a time with a 45-degree turning tool is not a problem for the turning tool.

Low-speed operation should also be employed while turning machinable ceramic threads, and the cutting quantity can range from 0.03 to 0.05mm per cut. Both high-speed steel and carbide steel cutter heads can be utilized when the feed rate and speed are appropriate, although carbide steel cutter heads are preferable. Geometric parameters of the tool are as follows:

Main declination f=80°
Offset angle f1=5°-6°
Knife inclination l=-2°
Rear angle a=10°-12°
Front angle g=15°-25°

Milling

Milling is comparable to turning. It uses carbide tools, takes a modest speed of 50 to 60 rpm, feed rate of 0.03-0.4 mm per revolution, and a maximum cutting depth of 3 mm. For milling planes, end faces, and spherical surfaces, the number of flutes makes no difference, but for smaller milling parts, a milling cutter with two flutes is superior to one with four.

Drilling

Drilling holes of various dimensions, the relationship between speed and feed rate is shown on the table below:

If you want to drill a larger hole, it is recommended to drill a small hole of about 1.5 mm first and a tapered surface of the same size as the hole on its bottom surface . This will prevent the surrounding material from collapsing during the drilling process, thereby improving the drilling effect. If not take above methods, fight on both sides or make a jigsawIt is feasible. Additionally, it is advisable to use 6, 8, and 10 drills in sequence when drilling larger holes.

When processing thin walls, start with the inner circle and support it with tools before processing the outer circle. High-speed steel, carbide drills, or carbide twist drills are all allowable. Flat drills (group drills) outperform pointed drills, and tungsten steel drills can be employed when considering efficiency.

The tapping of machinable ceramics differs from the tapping of metallic materials. The gap between the drilled and tapped holes of machinable ceramics should be bigger than that of metals. When tapping, the two sides of the thread in the hole are slopes, and tapping should always be performed in a single direction, never in reverse. After tapping, the workpiece should be rinsed in water and then the tap is reversed. A tap with four flutes performs better than that with two flutes. It is recommended that the tapping is carried out with water rush or even directly perform in water.

Sawing

A variety of saws can be used to process machinable ceramics. A hacksaw is a frequently used tool, and diamond and carbide saws are also available. Compared to other glass or ceramics, this machinable ceramic material is more than ten times easier to process. When using saw blades made of silicon carbide, the speed should be reduced.

Grinding

To avoid clamping too tightly and breaking during non-batch processing, cushion with kraft paper or sandpaper when clamping. The quickest and most cost-effective processing method of machinable ceramics is grinding, particularly when using diamond grinding wheels, which can keep the precise shape of the product and have a longer service life. Silicon carbide or aluminium oxide grinding wheels can also be utilized.

If a grinding wheel with a diameter of around 200 mm is employed, the speed can range from 300 to 2400 mm per minute, with 1800 mm per minute being preferred. The grinding wheel speed is 3600 rpm. It is recommended to use cooling water while grinding.

Finishing

To eradicate scratches on the machined surface, aluminium oxide or cerium oxide polishing powder can be used after washing for finishing on a thin, sticky cloth with a thickness of 6mm for approximately 15 minutes, and the surface roughness can reach 0.5. Round rod finishing can be wrapped with 0.05-0.10mm thin brass sheet, and the workpiece surface can be coated with 400-mesh silicon carbide paste.

Coolant

It is important to add an adequate amount of coolant to cool the material, such as saponified liquid, water, in order to achieve processed products with accurate tolerance. Use of specialized moulds is recommended for workpieces with intricate profiles and challenging processing. Drilling, turning, and milling can be done using high-speed steel tools without the need for water cooling. Turning, milling, and drilling using carbide-tipped tools are typically cooled with water or emulsion.

Introduction

Application

Material Properties

Introduction

Application

Material Properties

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Machinable Glass Ceramic

Machinable Glass Ceramic

Machinability

Thermal Stability

Electrical Insulation

Corrosion Resistance

Low Vacuum Outgassing Rate

Applications

Benefits

Innovation dedication

Insulating Parts

Key Parts of Lightning Rod

Welding Fixtures and Optical Glass Overmolding Molds

Vacuum Equipment Supports

Chemical Industry Components

Missile Gyroscope Coil Skeletons

Rotary Vacuum Pump Vanes