Overview of Ceramics Industry

A ceramic is an inorganic solid material, made up of either metal or non-metal compound. Traditionally ceramics were shaped and then hardened by heating to high temperatures. In general, they are hard, corrosion-resistant and brittle material.

What are Traditional ceramics?

The Traditional ceramics can be categorized as porcelain, earthenware, and stoneware. Pottery is one of the oldest used ceramic applications.

• Earthenware is used widely for ceramic such as tableware and decorative objects. It is one of the oldest Abrasion Resistant Material used in pottery.
• Stoneware clay is non-porous, glaze material applied only for decoration. It is a sturdy, chip-resistant and durable material.
• Porcelain is a very hard, translucent white ceramic. It also known as fine china products.
• Bone china – which is easier to make and is stronger than porcelain. It is made by adding ash from cattle bones to clay, or fine silica sand.

What are advanced ceramic materials? 

The Advanced ceramics are not clay-based material; however, these are highly advanced oxides or non-oxides or combinations materials used in various industrial applications:

• Oxides: alumina (Al2O3) and Zirconia (ZrO2).
• Non-oxides: Boron carbide (B4C), Silicon carbide (SiC) and Molybdenum disilicide (MoSi2).

Applications of advanced ceramics:

Advanced ceramic materials have been established in many areas of everyday use. These have utilization from fridge magnets to an increasing range of industries. Industries like including metals production and Abrasion Resistant Ceramic processing, aerospace, electronics, personnel protection and automotive have advanced ceramics application.

 

Quick Overview of CNC Machining Services

CNC stands for Computer Numerical control machining services that comprises of the computer which acts as the controller unit of the machine. In CNC machines the program of instructions is fed directly into the computer via keyboard. The programs are stored in the memory of the computer that can edit the programs as per the requirements. Traditionally, these machines were operated by experts in the operation of machining. In the CNC machines the role of the operators is minimized. These programs can be used for different parts, and can be repeated again and again. The CNC machine offers flexibility and computational capability.

Working of a CNC Machine:

The CNC Milling machine is comprised of the computer in which the programs are fed for metal cutting. All the cutting processes should be carried out according to the final dimensions to be fed into the computer via the program. The computer decides the operations to be performed and cutting processes.

Tools that run on the CNC are:

• Milling Machines
• Lathe
• Deep Hole Drilling 

The main purpose of these machines is to scrub off the metal and them a proper shape such as round, rectangular, etc. Most of the jobs need to be machined accurately, and the operator must be specialized to make the precision jobs. The operators have to feed the program of in the computer and load tools in the machine. Rest of the work is done automatically by CNC machine. 

Different Types of Machining Techniques

Those automated refinery devices which utilize industrial components without direct human support are the CNC machines. They make use of coded instructions sent to an internal computer, to allow fabrication of parts. This technology allows quick and accurate fabrication services to make a wide variety of parts. There are several types of CNC machines, ranging from plasma cutters to simple drills.

Types of Machines:

• Milling machines: These can automatically cut materials, including metal and cutting spindle. By following a computer controlled instructions, milling cutter can move to different positions and depths as directed.

• Lathes: It is the most prominent CNC machining tools, that is used for detailed machining operations. It makes use of automated tools that spin to shape the material in symmetrical sections.

• Grinders: It uses a spinning wheel to grind down materials. Grinders are very easy to program and are used where same precision is not required as mills or lathes.

In addition to above machining tools, there are also CNC routers, which are used for a variety of materials such as machining Thermal shock resistant materials. It makes use of computer programmable 3D printers, turret punches etc.

If you are seeking for quality the machining services, choose an industrial unit that has been in operation for a considerable length of time. In terms of machining a Thermal shock resistant material, experience matters for work quality. You must choose a reliable and trustworthy company for the best experience.

Various Applications of Machining Sapphire

Sapphire is an attractive substance, often considered a precious gemstone.  It  can be produced in comparatively large dimensions due to its inertness and therefore can be machined at high temperatures. It is often used as a material for the epitaxial deposition of Gallium and Silicon Nitride.

In the Machining Sapphire process require materials to be grounded to an appropriate size, tolerance and finely polished so that the material will be useful as planned. This process creates lots of difficulties in manufacturing challenge, it is always recommended to machine sapphire under expert supervision in order to succeed.

Industrial Applications of Sapphire: 

• It can be used for insulating substrate applications in high-frequency, high-power CMOS integrated circuits. 
• The resistance of sapphire to phosphoric or hydrofluoric acid is also significant.
• In endoscopic inspection tools, sapphire is often used as a window material.
• The fine microstructure of sapphire combined with polishing and skilled machining techniques produces cutter edges and ultra fine blade.
• Sapphire has a high degree of impact erosion, therefore it is used as a material for premium transparent watch face.
• Used in devices where corrosion resistance and high temperature is required.
• Stiffness, high hardness and single crystal structure lead to use of sapphire material in many engineering or industrial components. 
• Sapphire lenses can be used in imaging applications, laser optics, and sapphire medical optics.

Sapphire is a form of the material Alumina (Aluminium Oxide – Al2O3). It is the single crystal form of Machining alumina used in engineering ceramics. Its single crystal structure has no porosity or grain boundaries. Saphire products have a measured density, which is close to the hypothetical value of pure Alumina material.

Various Methods Used in Machining Ceramics

A ceramic is non-metallic, inorganic, crystalline oxide of nitride or carbide material. These materials are hard, brittle, and sturdy in compression and posses weak shear tension. When subjected to acidic or caustic environments, these can withstand chemical erosion. The most common type advanced ceramic materials are- Silicon Carbide, Alumina and Zirconia.

Methods of machining ceramic products involve:

1. Hot Pressing
2. Dry Pressing
3. Cold Static Pressing
4. Extrusion
5. Sintering and firing

• Hot pressing: This method involves application of pressure at high temperatures, to reduce voids. It helps in production of dense sintered bodies. It yields Thermal Conductivity Ceramics bodies of simple shapes.
• Dry Pressing: In this machining method, filling of the die is done with dried and granulated raw materials. Granulated raw materials fill a metallic mold cast and pressure is applied from the top. This method is ideal for mass-production of semi-complex machinery parts.
• Cold static Pressing: In this technique of machining ceramic, the granulated raw materials are poured into a rubber casting mould. This is later are subjected to hydraulic pressure, the pressure if applied evenly from all directions, results in Isostatic pressing.
• Extrusion: In Extrusion method dried and granulated raw materials are mixed with water and binder, plasticizing agent and dispersing agent. The resulting clay body is then extruded to final shape. This method is ideal for Thermal Conductivity Ceramic having a long product having continuous cross-sections.
• Sintering or firing: During the firing or sintering process, raw materials are heated below their melting point temperature to produce a sinter powder. Depending on the intended application, sintering methods are of types —vacuum sintering, atmosphere sintering and non-oxidizing sintering.

Tantalum- Most Unheard But Important Metal

Tantalum is the element sits between hafnium, niobium and tungsten in the transition metal section of the periodic table. It is discovered in 19^th century, named after Tantalus, a figure from Greek mythology. It has atomic number 73, atomic weight 180.94, atomic symbol ‘Ta’ and it is a high density metal. Tantalum is increasingly becoming important in the 21^st century, as it plays a crucial role in making electronic devices smaller. It naturally fights corrosion.

Tantalum is rarely found in its elemental form. It is one of the high density metals, found with niobium and other radioactive elements uranium and thorium. Several industrial processes are required to extract   pure tantalum. Australia and South America account for over two-third of the world’s tantalum production. A single mine in Brazil accounts for 20% of the total annual supply. Due to the increase in the use of tantalum in electronics devices,   the cost of capacitor grade tantalum has also increased over the past decade.

This element remains very stable at temperature lower than 150 degree Celsius. It has a natural protective layer created by  tantalum oxides to protect it from corrosion. Due to the corrosion resistant property it is highly used in making of bridges and water tanks. Tantalum capacitors have very high capacitance packed in a small volume which makes it perfect for reducing the size of the electronic devices. It is found in DVD players, cell phones, hard drives, laptops and PS3.

Tantalum is used in making devices used in television, cell phones and surface acoustic wave filters. The average cell phone has about 40 milligrams of tantalum inside it. Its capacitors has very low failure rate making them accurate for manufacturing of medical equipment.  It is also used in making knee, hip and other orthopedic implants.

Benefits of CNC Machining

The CNC stands for Computer Numerical Control, is a process of machining substances  that involves computer aided technology to control tools. Tools that can be controlled in this manner include grinders, lathes, mills and routers. In this technology the computer's unique software and control console sets the system apart for use in CNC machining.

In CNC Machining the machine tools function through numerical control in which a computer program is customized for an object to be machined. The machines are programmed with a CNC machining language called G-code. This controls all features like location, feed rate, coordination, and speeds. This technology is utilized in manufacturing both metal and plastic parts for Custom Machining Services.

The main benefits of using CNC Machining is that, this process is more precise than manual machining methods. As it delivers precision machining, this process can produce complex shapes that would be almost impossible to achieve with manual machining

Below are major benefits of CNC Machining Process:

1)      Cost savings:  It  allows the operator to take full advantage of raw materials. More accuracy is delivered and less waste is produced. Therefore, it minimizes the loss and increases profit over costs.

2)      Speed:  This technology has fastened the machining process. It can quickly produce parts that would normally take multiple steps to manufacture by manual process.

3)      Improved Efficiency:  CNC machines are the most efficient mean to deliver quality and Precision machining services. The minute an error can be detected in the product therefore leads to optimum raw material usage.

4)      Safety:  As the entire process is automated, There is complete safety of operators and workers, allowing a safer work environment.

This technology is also utilized for the jobs that need a high level of precision. It is because of these qualities that CNC Machining is used for the production of many complex three-dimensional shapes.

Mechanical and Physical Properties of Zirconia

Zirconia is also known as Ceramic steel. It posses the transformational and toughening system, which doesn't occur in any other ceramic material. According to many researchers the development and marketing effort has been expended on this single material which offers the traditional ceramic advantages of hardness, wear resistance and corrosion resistance, without the characteristic ceramic property of absolute brittleness.

Elementary properties of zirconia ceramic which makes it highly usable ceramic:

·        High hardness

·        High strength

·        Electrical insulation

·        Very high wear resistance

·        High fracture toughness

·        Excellent frictional behavior

·        Extremely non-magnetic nature

·        Low thermal conductivity

·        Modulus of elasticity equal to steel

·        Coefficient of thermal expansion similar to iron

·        High corrosion resistance in alkalis and acids

In familiar with all other engineering ceramics, the achievement of these properties is mostly reliant on both the initial powders and the fabrication methods. These outstanding properties advance and enhance the machining zirconia process. As it leads to perfect machining of the material. Therefore, it is a highly machinable ceramic material.

All commonly used ceramic consolidation methods can be applied to zirconia ceramic. Some of these techniques are iso-static pressing, dry pressing injection moulding, extrusion tape casting and dry pressing. Fault elimination at all development stages is essential for not only reliability but also high strength.  


With decisive flaws of the order of 45 µm, clean room technique has been shown to drastically improve both distribution of strengths and mean strengths. The values of about 1500 MPa bending strength with modulus 30 have been recorded for various zirconia ceramic materials. 

Role of Tungsten in Future

Tungsten having symbol W and atomic number 74 is one of the ostensible transition metals. The shiny gray metal remains solid in state at room temperature. Tungsten is characterized by unique chemical and physical properties. The requirements of a more energy conscious world in relation to the efficient consumption and production of energy has escalated in past years and will become increasingly significant for the society in the future.

Presently, worldwide energy consumption is growing much faster than the overall supply. The effectiveness of conventional technologies should be enhanced in order to decrease losses in distribution and transmission of energy. New technologies and strategies must be developed for ‘Using less & doing more’. Whatever new solutions may be developed in the future, it can be expected that tungsten based components and materials will surely play their constructive part in meeting these obstacles.

Tungsten products have contributed a lot in the past both as advanced tools and functional materials with marvelous properties. This contribution will not reduce in the approaching future. Recent deliberations on global warming and the conclusion that some greenhouse gases are responsible for the majority of observed temperature increase since the starting of twentieth century, have brought reduction calls in emissions which will stipulate a more careful handling of fossil energy globally.

The search for substitutes will be increased, as oil, coal and natural gas reserves are being depleted and the necessity to use existing renewable and natural resources is also gradually increasing. In near future, there is a huge opportunity for tungsten containingproducts which have tactical significance in the field of fossil energy, power transmission, fossil energy production, or renewable power generation, and power distribution, because of their brilliant properties. 

Sapphire- An Element with Unique Properties

Sapphire is one of the most durable, hardest and scratch-resistant materials. It was first synthesized in 1902. The process of making synthetic Sapphire is called as Verneuil process. Only experts can differentiate between synthetic and natural Sapphire. It offers a broad transmission range from Ultra Violet to mid infrared wavelengths (250–4500 nm). The material is able to bear up extreme temperature changes and environmental conditions.

The most valuable color of Sapphire is a cornflower blue color, also known as Cornflower Blue Sapphire or Kashmir Sapphire. A unique type of sapphire, known as color changing Sapphire, shows various color patterns depending upon the lightening. In natural light, it is blue, but in artificial light, it is violet. Pink and yellow Sapphire has recently become very popular, and is often used in jewelry.

Sapphire mainly consists of minor inclusions of minute slender Rutile needles. These inclusions decrease the transparency and clearness of a stone and are called as silk. In dense and parallel groupings, the inclusions can actually improve by allowing polished Sapphires to exhibit asterism (a prominent star like pattern). Sapphire gems displaying asterism are called as ‘Star Sapphires’, and these are highly expensive.

It is pleochroic, displays an intense and lighter color when viewed at different angles. Some pleochroic Sapphire is purple when viewed at one angle, and blue at a different angle. Color zoning, which is created from growth layers that build up at the time of the formation of the stone, may also be present in certain Sapphires. Color zoning is certainly responsible for darker and lighter colors of Sapphire. Many Sapphire gemstones are even multicolored such as pink, blue and purple.

Machining sapphire is very complex and difficult process. Its machining requires special types of tools and techniques. An ideal machining procedure is possible only if favorable conditions are provided. Diamond tooling method is highly used in machining sapphire. It is a tough and durable element and  only natural gemstone harder than Diamond. Inspite of this, Sapphire is still subject to fracture and chipping if handled roughly.  

Reasons to choose Ceramic Capacitors over Tantalum Capacitors

The extensive use of ceramics represents a milestone in the history of electronics. Tantalum capacitors are used in electronics because of high melting point, high capacitance and high density. It is corrosion resistant to most acids at different temperatures. All these unique features have made tantalum increasingly useful over the years, especially in nano electrical circuitry.

But the scarcity of tantalum powder has boosted the demand for alternate components. After using tantalum parts for many years, manufacturers suddenly wanted other alternate options. The development and research efforts lead to the improvement in engineering and production methods for ceramic capacitors. As a result, there were the surprising improvements in design combined with the inherent uniqueness of ceramics.

The design modifications led to numerous advantages, which includes low ESR (equivalent series resistance), non polarization, ease of placement and high voltage. The Low ESR is vital because it lets manufacturers to use lesser-value capacitors without corrupting performance. However, the more important fact is that the ceramic capacitors are very cost efficient. Customers realized that the design flexibility offered by ceramics is better than tantalum capacitors.

The designs of ceramic caps are easily adjustable, which allows the drop-in replacements in filtering, smoothing, decoupling and by-passing and applications. Ceramic caps can be easily customized in a cost-effective manner. However, it is not possible for tantalum because machining tantalum consumes lots of time and is expensive. The lead time dropped from 52 weeks for tantalum caps to eight weeks for ceramics.

Small capacitors can't attain the same capacitance as larger ones. They do need fewer raw materials. Reduced demand for raw material lessens the possibility of a material shortage which increases cost. As tantalum capacitors are much larger than the ceramic using ceramic caps can reduce equipment size and cost. Other benefit is that the electrode material nickel used to make ceramics is much easier to mine and find than tantalum.

The future of ceramic capacitors is very bright. As consumers gets attracted to more sophisticated products and smaller size, manufacturers are now giving importance to the size, design flexibility and cost of capacitors. Although tantalum is still a useful material, ceramics have established their mark in the market. 

Handling Instructions during Quartz Glass Machining

Like conventional glass, quartz glass does not contain soda or calcium oxide, instead it consists   pure silica. In an industrially produced quartz glass, a distinction is made between synthetic (fused silicon dioxide) and natural (fused quartz) origin. Industries generally manufacture primary materials with different concentrations of impurities in the ppm (parts per million) range.

Quartz glass is formed by melting quartz sand of excellent purity (Silicon Dioxide content of 99.97%) and then allowing the melt material to solidify and cool down. Semi-finished products made from quartz glass have many extraordinary properties.  This makes quartz glass best for high-quality goods and ideal for  a wide range of applications.

Instructions during Machining:

• To maximize service life: We can increase the life expectancy of quartz glass products by keeping them neat and clean. Even a smaller amount of impurity present on the surface of a product can cause the whole area to be devitrified when the product is heated. This also increases the devitrification of other areas and shortens the service life of product. Quartz glass products are mostly used for high-temperature operations and in processes where high purity is necessary. Therefore, while machining quartz glass, it is very important to handle the products in a clean working environment.

• To maintain a safe working environment: It is highly recommended that do not handle quartz glass products with uncovered hands. We should protect the glass products from dust and dirt during storage and keep them in plastic bags.

        

1)    Use a dust control device or wear a dust mask during slicing or/and grinding as dust particles will be created.

2)    Handle the products very carefully as they are made up of glass.

Different Ways Of Machining Molybdenum

Molybdenum is a element with symbol ‘Mo’ and atomic number 42. Its name has been derived from Neo-Latin word ‘molybdaenum’ meaning lead, and was discovered in 1781 by Carl Wilhelm Scheele. It does not occur naturally as a free metal, and only found in different oxidation states. Machining molybdenum can be done through common metal machining processes, and therefore, no individual methods or equipments are required to produce parts with accurate dimensions.

• Tools for machining molybdenum: For machining molybdenum, tools should be sharp, firmly chucked and well supported. The machines should be sufficiently powerful, rigid and free from backlash. Tools life is shorter than expected   as molybdenum is more abrasive than other metals. It has the tendency to chip while being machined. 

• Lubricants: Machining is done without lubrication, but if they are used, the tool life can be increased and so do the cutting speed. It helps in removing fine molybdenum particles from the tools. Use of lubricants makes the various high- chlorinated oils and solvents effective in various processes of band saw cutting, turning, in reaming, drilling, tapping and in hacksaw. Sulfur-based cutting oils cannot be used in machining, electronic parts because of their poisonous effect on final properties.

• Sawing and shearing: Sawing molybdenum is the practice of that used for super alloys. The use of a soluble oil, coolant is the band saw or hacksaw cut removes the chips and lengthens the blade life. The most efficient blades used for sawing are high speed steel blades with only one tooth area.

• Milling and shaping: Milling and shaping of molybdenum is done with carbide grading tools which are normally used for casting iron. Face Milling is effective for machining plain surfaces. 

• Drilling reaming and threading: Two- lipped carbide drill is generally used for drilling. Cutting oil should be used for all the tapping, reaming and drilling purposes. Reaming is a very difficult process, the tool life is very low as compared to the other machining processes. Threading can be done in various ways. Thread cutting with single tool is one of the most popular ways. 

• Electropolishing and photoetching: The Electropolishing of molybdenum is done using two most commonly used acids- Sulphuric acid and phosphoric acid. They both provide better finishing. The baths using these acids are done under room temperature with molybdenum as anode. The photoetching process mainly done by conventional methods. It is either done chemically or electrolytically. 

Common Properties & Applications of Low Thermal Expansion Materials

Thermal expansion is the tendency of a material to change in shape, volume and area in response to the change in temperature. Fine ceramic products used to have low coefficients of thermal values in respect to changes in temperature, which depends on the bond between the atoms of the materials.

Ceramic is a known low thermal expansion material and poses excellent thermal, mechanical, chemical and electrical properties. Some common machinable ceramics are Macor, Macerite, Photoveel and more. Macor has high electrical resistivity, high dielectric strength and can withstand temperature upto 1000 degree Celsius. It can easily be machined into complicated shapes and precision parts using different traditional machining tools.

Non-machinable ceramics such as high purity Alumina, Zirconia, Aluminium Nitride, Silicon Carbide, Silicon Nitride, Boron Nitride, and more also used in various applications. It requires best ceramic machining tools and equipment such as 3 and 5 axis machining centers as well as precision measuring instruments in order to deliver quick results without compromising on the quality part.

For machining Ceramics, companies generally employ diamond tools, machining centers and jigs which are especially designed and produced to perform shaping, carving, embossing, grooving, hole drilling and tapping effectively. Many companies also use slicing machines to cut low thermal expansion materials effectively as it is not only affordable but also reduce wastage of material during the process.

Machining ceramics require clean rooms equipped with vacuum constant temperature drying machine, hot air drying machine, de-airing sealer and 5 tanks deionized water ultrasonic cleaning machine to meet requirements of the semi-conductor industry.