Department of Ceramic Technology - AC Tech Campus - Anna University, Chennai

Infrared (#IR) spectroscopy is an #analytical technique used to identify and study the #composition of substances based on their interaction with infrared light. It is commonly used in #chemistry, #biochemistry, and various fields of material #science. Here’s a basic overview of how #IR_spectroscopy works, its principles, and its applications: Principles of IR Spectroscopy Molecular Vibrations: #Molecules consist of #atoms bonded together, and these bonds can vibrate in different ways (stretching, bending, twisting). When infrared radiation is passed through a sample, certain wavelengths of IR light are absorbed by the molecules, causing these vibrational modes. #Absorption of IR Light: Only specific frequencies (or wavelengths) of IR light correspond to the vibrational transitions of particular molecular bonds (e.g., C–H, O–H, N–H bonds). The absorbed wavelengths are characteristic of certain functional groups and can be used to identify them. Instrumentation: An IR #spectrometer typically consists of an infrared light source, a sample holder, a detector, and a computer for data #analysis. The sample can be a solid, liquid, or gas. The key components include: Source: Produces #infrared radiation (e.g., a #Nernst glower or a globar). Interferometer: In Fourier Transform IR (#FT_IR) #spectroscopy, an interferometer is used for increased #sensitivity and quicker analysis. #Detector: Measures the intensity of the transmitted or absorbed light. The #IR_Spectrum The output of IR spectroscopy is a #spectrum that displays intensity (absorbance or transmittance) on the y-axis and frequency (usually in #wavenumbers, cm⁻¹) on the x-axis. #Peaks in the spectrum correspond to the #absorption of specific wavelengths of IR light, and their position and intensity provide information about the molecular structure and functional groups present in the sample. Key Functional Group Regions Certain regions of the #IR_spectrum are associated with vibrations of specific functional groups: O-H Stretch (#Alcohols, #Phenols): Broad peak around 3200-3600 cm⁻¹. N-H Stretch (#Amines, #Amides): Peaks around 3300-3500 cm⁻¹ (usually sharp). C-H Stretch (#Alkanes, #Alkenes, #Aromatic): Varies, typically 2800-3000 cm⁻¹. C=O Stretch (#Carbonyl compounds): Sharp peak around 1700 cm⁻¹ (exact position varies with the type of carbonyl). C=C Stretch (Alkenes, Aromatics): Peaks around 1600-1680 cm⁻¹. C–N Stretch (Amines, Amides): Peaks around 1200-1350 cm⁻¹. Applications of IR Spectroscopy Identifying Functional Groups: By analyzing the spectrum, #chemists can identify functional groups and infer information about the #molecular #structure. Material #Analysis: It can be employed to study #polymers, coatings, and other #materials to understand their #composition and properties. Biomedical Applications: In #biochemistry, IR spectroscopy aids in studying #biological molecules like #proteins and #carbohydrates.

Fracture Toughness is a material property that describes the ability of a material containing a crack to resist fracture. It's a critical parameter in the design of components where structural integrity is paramount, especially under conditions involving stress concentrations, like cracks or notches. Here are some key points: 1. Definition: Fracture Toughness (K_IC): Often denoted as KIC, it represents the critical stress intensity factor at which a crack in a material begins to grow in an unstable manner. KIC is used for materials exhibiting linear elastic behavior up to fracture. Units: Measured in MPa√m (megapascals square root meter) or ksi√in (thousand pounds per square inch square root inch). 2. Types of Fracture Toughness: Plane Strain Fracture Toughness (K_IC): This is the most common measure, applicable when the thickness of the material is large enough that the stress state around the crack tip is plane strain. This condition ensures the least conservative (most severe) fracture toughness value. Plane Stress Fracture Toughness: Occurs in thinner sections where the stress state at the crack tip is plane stress. Here, the fracture toughness might be higher than KIC. Dynamic Fracture Toughness: Relevant for high strain rates where the material's response to rapid loading is considered. 3. Factors Affecting Fracture Toughness: Material Type: Ductile materials generally have higher fracture toughness than brittle materials. Microstructure: Grain size, phase distribution, and the presence of inclusions or precipitates can influence toughness. Temperature: Some materials become brittle at lower temperatures (ductile-to-brittle transition). Loading Rate: Faster loading rates can lead to lower toughness in many materials. Environmental Conditions: Exposure to corrosive environments can reduce toughness through mechanisms like stress corrosion cracking. 4. Testing: Fracture toughness is typically measured using standardized tests: Single Edge Notch Bend (SENB): A notched beam is bent until fracture. Compact Tension (CT): A standardized specimen where a load is applied to pull apart a notched sample. ASTM Standards like ASTM E399 or ISO 12135 provide guidelines for these tests. 5. Importance: Design: Helps in determining the critical size of a flaw that a component can tolerate before failure, crucial in preventing catastrophic failures. Material Selection: Guides the choice of materials for applications where toughness is critical, like in aerospace, automotive, and structural engineering. Safety: In safety-critical applications, materials with high fracture toughness are preferred to avoid sudden failures. Follow HORIZON TITANIUM INC.

Ceramic Manufacturing Process in a few Steps: Manufacturing ceramics requires precision and expertise at every stage, including forming, firing, and glazing. Ceramic manufacturing is a complex process that involves using advanced materials and techniques to create a wide range of products. The fundamental procedures are purchasing raw materials, beneficiating them, mixing, forming, green machining, drying, thermal processing, glazing, firing, and final processing. 1. Raw Material Procurement: Raw materials are transported and stored at the manufacturing facility. Ceramics are made from moderately impure clay materials extracted from natural sources to extremely pure powders created through chemical synthesis. They are produced from silica, sand, quartz, feldspar, and aluminosilicate. 2. Beneficiation: After raw material procurement, beneficiation is the next. This step focuses on the techniques used to refine naturally available raw materials. Some fundamental beneficiation processes are: Comminution Purification Sizing Classification Calcining Liquid dispersion & Granulation. Before being transferred to a ceramic manufacturing facility, naturally occurring raw materials are frequently subjected to some beneficiation at the mining site or an intermediate processing facility. These processes help to eliminate undesirable impurities and ensure a steady supply of raw materials of the required purity. 3. Mixing: Mixing is used to blend ceramic powder components to create a more uniform material for chemical and physical shaping. Binders and plasticisers make dry powder and plastics; deflocculants, surfactants, and antifoaming agents are added to slurry processing to facilitate processing. 4. Forming: There are many forms of ceramics, for example slip casting. Here, a plaster mould is filled with slip or liquid clay. The water is drawn out of the plaster mould's walls, leaving a layer of solid clay inside. Firm clay can be removed once dried. There are many other forming techniques used in the ceramic manufacturing process. These techniques include, Dry pressing, Isostatic pressing Tape casting Slip casting Gel casting Extrusion & Injection moulding. These techniques rely on organic additions to the ceramic mix to shape the material into the desired form. The specific forming technique depends on the ceramic product's manufacturing type and application. 5. Green Machining: refers to the process of shaping a ceramic part while it is still in its “green” or un-sintered state, applying ultra-hard, high-performance cutting materials. Allows for the creation of complex shapes and features that may not be possible using traditional forming techniques. Also allows for tighter tolerances and higher precision in the final product. After green machining, the ceramic part is dried and fired to achieve its final properties. https://lnkd.in/g9BfTE7P

🎯🎯Falling rate period🎯🎯 During this period, there is no continuous flow of water from inside to the suraface through the filled up pores, which themselves start losing their water. So there is evaporation within the solid and the vapour reaches the surface by diffusion through the pores and the film of stagnant air. The driving force is the vapour pressure gradient caused by equilibrium with the liquid in the capillaries or pores. The drying rate varies with the diffusion rate. The rate of drying in the falling rate period is often a linear function of moisture content. 💥💥Type of driers💥💥 Since drying is an expensive operation, the main objective of commercial driers has been to carry out the operation uniformly in the shortest time possible with the maximum number of articles. Depending on the volume of production and the shape and size of the articles. Two general types of driers are used: 1.  Chamber drier and 2. Continuous or channel drier 💥💥Chamber Drier💥💥 In the chamber drier, the ware is set in the drier and remains stationary. Slow-speed fans blow air heated by passing over steam coils, through adjustable louvers, through the wares. Reversal of the fan, at suitable intervals of time, more or less ensures an even drying. The temperature and humidity can be controlled by suitably adjusting the volume and temperature of the inlet and outlet air or gases. Sanitarywares are dried in chamber driers. 💥💥Continuous or channel Drier💥💥 In continuous driers the wares move through a channel or tunnel on cars or conveyors. The wares thereby are subjected to a sequence of conditions as they move along. While increased cross-section of the channel or tunnel accommodates increased units of wares when stacked in layers, it also correspondingly increases the time required to obtain uniformity. So, either the holding time at a temperature, i.e., the total drying time, has to be increased or the total length of the tunnel has to be increased. The bigger the cross-section of the tunnel, the greater the need for uniform distribution of the heat supplied for drying. Rapid drying is possible only if the ware is thin and passes through a single layer. 💥💥Drying Practice In Sanitaryware💥💥 In casting, the wares are removed from the moulds as soon as they are set. Thereafter they go separately for drying. The most common practice is to leave the casts and moulds in the casting shop overnight when the temperature and humidity of the shop is controlled. Thereafter the moulds placed on trolleys dry in the hot room and the casts are dried in the humidity drier. #ceramics #drier #sanitary_ware #tiles #table_ware

#Bioceramics New ways of providing assistive care to fractures and damaged tissues are key areas in nanomedicine and tissue engineering. There is a wide class of materials known as bio-ceramics, which are excellent materials for many types of reconstructive and regenerative medicine. In this article, we look at what they are and some of the application areas where they are used. What Are Bio-Ceramics Bio-ceramics are a class of materials composed of biocompatible ceramics and bioglasses, with some of the most common bio-ceramics being calcium phosphate, hydroxyapatite, polymer composites, bioactive glasses, zirconia, titania and alumina. The materials in this class range are often harder in structure but can either be densely packed or porous depending on the required application. It should be noted that the ceramic-like materials bear no resemble to porcelain-type ceramics, rather, they are materials that mimic the body’s own biomaterials (or are durable metal oxide materials). Applications of Bio-Ceramics Many of the applications are in assistive repair, so there are certain characteristics that bio-ceramic materials need to exhibit for them to be used in clinical applications. The most important is biocompatibility, so that they can help to prevent the body’s natural defence system from breaking them down and they are not toxic to the cellular environment when they are used. Other properties include a high wear resistance which utilizes a materials high hardness and a lack of plastic and elastic deformation under a load, a low friction coefficient, a high compressional strength, a high fatigue resistance, high biological and chemical corrosion resistance, high electrical insulating properties to prevent galvanic reactions from occurring and the ability to synthesize a highly pure material one Regeneration and Reconstruction A wide range of materials can be employed in bone regeneration and reconstruction approaches, depending on the bone in question and the level of damage. To date, alumina, metal bioglass, bioglass-metal fiber composites, polymer-carbon fibre composites, calcium phosphate and hydroxy apatite have been used in these approaches. These materials have been used for a wide range of functions, including as both dense materials for direct implants and reconstruction materials (plates etc) and as porous materials to help the native bone cells to regrow naturally. As a class of materials, bio-ceramics can be used in reconstructive approaches as a total artificial replacement for the hip, knee, shoulder, elbow and wrist, as bone plates, bone screws and bone wires, as intramedullary nails to repair fractures, Harrington rods to correct spinal curvature, vertebrae spacers and extensors to correct congenital deformity, as a way a fusing the spine to protect the spinal cord, alveolar bone replacements, mandibular reconstruction, dental implants to replace damaged, removed or decaying teeth and as orthodontic anchors.

#Calcium_zirconate (CaZr03) powder, a type of zirconate compound, has various applications in different fields. Some of its notable applications include: Solid Oxide Fuel Cells (SOFCs): CaZrOg powder is used as an electrolyte material in solid oxide fuel cells due to its high oxygen ion conductivity and chemical stability at high temperatures. It helps in enhancing the performance and efficiency of fuel cells. Ceramic Industry: Due to its excellent thermal stability, high melting point, and chemical resistance, calcium zirconate powder is used in the ceramic industry. It can be employed in the production of high-temperature ceramics, ceramic pigments, and refractory materials. Thermal Barrier Coatings (TBCs): CaZrO3 powder is used as a material for thermal barrier coatings, which are applied to components in gas turbines, diesel engines, and other high temperature environments. These coatings help in reducing the operating temperature of the coated components, thereby extending their lifespan. Catalysts: It is also used as a catalyst in various chemical processes, including the production of hydrogen, ammonia, and other chemicals. Its stability and catalytic properties make it suitable for these applications. Electroceramics: CaZrO3 powder is used in the production of various electroceramic components, such as capacitors, resonators, and dielectric resonators. Its dielectric properties make it suitable for these electronic applications. Advanced Ceramics: It is utilized in the production of advanced ceramics used in various high-temperature applications, including aerospace components, cutting tools, and wear-resistant parts. Medical Applications: Calcium zirconate powder has been investigated for potential biomedical applications such as bone graft materials and dental applications due to its­­­­­­­­­­­-­­

#The_flexural_strength_test for porcelain tiles is a crucial mechanical test that measures the tile's ability to resist bending or flexing without breaking. This test helps assess the tile's structural integrity and its suitability for various applications, especially in situations where tiles might be subjected to bending forces, such as when installed on floors or walls. The test involves applying a controlled load to a supported tile specimen until it fractures. Place the tile specimen on the bending fixture with its glazed surface facing upwards. The support points should be positioned under the tile at specific distances from each other, and the loading point should be placed on the centerline of the span between the support points. Gradually apply a force or load at a constant rate onto the center of the tile using a hydraulic or mechanical testing machine. The rate of loading is controlled to apply stress to the tile in a consistent manner. The test continues until the tile specimen fractures. The point at which the tile breaks and the applied force at that point are recorded. This breaking point provides information about the maximum load the tile can withstand before failure. The calculated flexural strength value provides insight into the tile's ability to resist bending forces. It helps determine whether the tile meets the required standards for its intended application. Tiles with higher flexural strength values are generally more durable, suitable for high-stress environments with ensure long-lasting performance and safety.

#Stain_Test The stain test for porcelain tiles is a method used to assess the tile's resistance to staining from various substances. Porcelain tiles are often used in spaces where they might come into contact with liquids, oils, and other materials that could potentially cause stains. This test helps evaluate the tile's ability to repel or resist absorption of these substances, maintaining the aesthetic appeal and cleanliness of the tile's surface. A range of substances that are likely to come into contact with the tile's surface is chosen for the test. These substances can include common household items like red wine, coffee, ketchup, oil, ink, and more. The goal is to simulate real-life scenarios that might cause stains.

#Rectangularity_test The rectangularity test for porcelain tiles evaluates how closely a tile's edges and corners conform to a true rectangular shape. This test is important because tiles with accurate rectangularity are easier to install, resulting in consistent grout lines and a visually pleasing finished appearance. The test helps ensure that tiles fit together tightly and evenly, minimizing the potential for lippage (uneven edges between adjacent tiles). A rectangularity gauge or template is used to assess the tile's conformity to a true rectangular shape. This template typically consists of two perpendicular arms that form a right angle. Place the selected tile on a flat and level surface with its glazed side facing upwards. Position the rectangularity gauge or template over the tile in such a way that the arms of the gauge align with the edges of the tile. Compare the edges and corners of the tile to the gauge or template. This is a qualitative assessment of how well the tile's shape matches the right angle formed by the template. Rectangularity testing helps ensure that the tiles fit together tightly and evenly during installation, creating a cohesive and visually pleasing surface. It's particularly important for applications where precise alignment is crucial, such as large-format installations. By assessing and categorizing tiles based on their rectangularity, manufacturers and users can make informed decisions about how to use the tiles effectively and achieve the desired aesthetics and functionality in their projects.

#Advanced_structural_ceramics Advanced structural ceramics, including oxide-, carbide-, nitride- and boride-based systems, are characterized by high strength, stiffness, hardness, corrosion resistance, and durability. Such ceramics retain these properties at high temperatures, making them ideal for a wide range of demanding applications, including engine components for subsonic aircraft (combustor liners, exhaust-washed structures, high temperature ducts, heat exchangers, and nacelle insulation) and airframe and propulsion systems for high-speed vehicles. The primary benefit of structural ceramic materials is the ability to withstand higher temperatures, which improves propulsion system efficiency, increases lifetime, enables. Some examples are: Oxide composites with operating temperatures as high as 1250°C and lifetimes of thousands of hours in highly oxidizing combustion or reentry environments are very suitable for some engine components, warm structures, and thermal management components. Non oxide composites made of silicon carbide reinforced either with carbon fibers or a combination of carbon fibers and silicon carbide fibers are capable of operating temperatures of 1300°C-2000°C for short times in highly oxidizing environments or for much longer times near the lower end of the thermal range when protected with environmental barrier coatings. Furthermore, because non oxide fibers exhibit higher strength and better strength retention than oxide fibers, they are being widely researched for application in combustion environments as well as for hot structures of hypersonic and reentry vehicles.