http://www.substech.com/dokuwiki/ 2012-02-04T06:38:11-05:00 http://www.substech.com/dokuwiki/ http://www.substech.com/dokuwiki/lib/images/favicon.ico text/html 2012-01-28T06:35:42-05:00 http://www.substech.com/dokuwiki/doku.php?id=tribology_of_polymers&rev=1327750542&do=diff1327750542 Discuss the article and ask questions in our Materials Forum to Polymers Dr. Dmitri Kopeliovich Tribology is the science and engineering of rubbing surfaces. Polymer is a substance (natural or synthetic), molecules of which consist of numerous small repeated chemical units (monomers) linked to each other in a regular pattern. text/html 2012-01-14T15:48:29-05:00 http://www.substech.com/dokuwiki/doku.php?id=latest_articles&rev=1326574109&do=diff1326574109 * Surfactants - 2012/01/14 * Alkaline cleaning - 2012/01/7 * Diamond-Like Carbon - 2011/12/24 * Anti-stiction coatings for MEMS - 2011/12/17 * Adaptive tribological coatings - 2011/12/8 * Geometrical parameters of engine bearings - 2011/12/1 * Tribological properties and applications of alumina - 2011/10/17 * Enhancement of adhesion - 2011/10/09 * Fabrication of Ceramic Matrix Composites by Liquid Silicon Infiltration (LSI) - 2011/09/02 * Black copper oxide coating - 2011/08/08 * Tribo… text/html 2012-01-14T15:48:02-05:00 http://www.substech.com/dokuwiki/doku.php?id=full_index_of_articles_on_fluids&rev=1326574082&do=diff1326574082 back to Contents * Lubricants * Classification of lubricants * Additives in lubricating oils * Biodegradation of oils * Engine oils * Gear oils * Hydraulic oils * Cutting fluids (coolants) * Way lubricants * Compressor oils * Rust protection oils * Quenching and heat transfer oils * Transformer oils (insulating oils) * Solid lubricants * Graphite as solid lubricant * Molybdenum disulfide as solid lubricant * Boron nitride as solid lubricant … text/html 2012-01-14T15:47:33-05:00 http://www.substech.com/dokuwiki/doku.php?id=surfactants&rev=1326574053&do=diff1326574053 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Surfactant (surface active agent,detergent) is a substance reducing the interfacial energy of the solution in a contact with other phases. Surfactants promote dispersion of various phases: emulsification of oils (liquid phase), suspension of solid residuals (solid phase) in the alkaline cleaners and foaming (gaseous phase). text/html 2012-01-14T15:46:30-05:00 http://www.substech.com/dokuwiki/doku.php?id=stabilization_of_colloids&rev=1326573990&do=diff1326573990 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Colloidal particles collide with each other due to the Brownian motion, convection, gravity and other forces. Collisions may result in coagulation of the particles and destabilization of the colloid. If a colloidal particle is brought to a short distance to another particle, they are attracted to each other by the van der Waals force. If there is no counteracting force, t… text/html 2012-01-14T15:46:05-05:00 http://www.substech.com/dokuwiki/doku.php?id=coagulation_of_colloids&rev=1326573965&do=diff1326573965 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Coagulation is the destabilization of Colloids by neutralizing the electric charge of the dispersed phase particles, which results in aggregation of the colloidal particles. Aggregation is a formation of groups of particles (aggregates) bonded to each other by van der Waals or other intermolecular forces. Aggregation usually refers to solid particles. If a coagulation of… text/html 2012-01-14T15:45:47-05:00 http://www.substech.com/dokuwiki/doku.php?id=preparation_of_colloids&rev=1326573947&do=diff1326573947 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich The size of dispersed phase particles in Colloids is within the range 1 - 1000 nm (4*10-8 - 4*10-5 inch). There are two principal ways of preparation of colloids: text/html 2012-01-14T15:45:28-05:00 http://www.substech.com/dokuwiki/doku.php?id=lyophilic_and_lyophobic_colloids&rev=1326573928&do=diff1326573928 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Depending on the affinity of the dispersion media for the dispersed phase two types of Colloids exist: * Lyophilic colloids * Lyophobic colloids text/html 2012-01-14T15:44:45-05:00 http://www.substech.com/dokuwiki/doku.php?id=brownian_motion_and_diffusion_in_colloids&rev=1326573885&do=diff1326573885 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Brownian motion is the seemingly random movement of particles suspended in a dispersion media caused by collision with its molecules. Due to Brownian motion the colloidal particles are capable to move (diffuse) from the regions with higher concentration to the regions with lower concentration of the dispersed phase. The diffusion flux according to the First Fick’s law… text/html 2012-01-14T15:44:24-05:00 http://www.substech.com/dokuwiki/doku.php?id=colloids&rev=1326573864&do=diff1326573864 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Colloids are micro-heterogeneous dispersed systems, in which the size of the dispersed phase particles is within the range 1 - 1000 nm (4*10-8 - 4*10-5 inch). The colloids phases (dispersion medium and dispersed phase) can not be separated under gravity, centrifugal or other forces. Dispersed phase of colloids may be separated from the dispersion medium by micro-filtratio… text/html 2012-01-14T15:43:50-05:00 http://www.substech.com/dokuwiki/doku.php?id=classification_of_dispersions&rev=1326573830&do=diff1326573830 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Dispersion (dispersed system) is a mixtures of two substances, one of which (dispersed phase) is distributed in form of subdivided particles throughout another substance (continuous phase, dispersion medium). text/html 2012-01-14T15:41:26-05:00 http://www.substech.com/dokuwiki/doku.php?id=dispersions&rev=1326573686&do=diff1326573686 Discuss the subjects and ask questions in our Materials Forum to Fluids * Classification of dispersions * Colloids * Brownian motion and diffusion in colloids * Lyophilic and lyophobic colloids * Preparation of colloids * Coagulation of colloids * Stabilization of colloids * Surfactants text/html 2012-01-14T15:40:38-05:00 http://www.substech.com/dokuwiki/doku.php?id=playground:playground&rev=1326573638&do=diff1326573638 Discuss the article and ask questions in our Materials Forum to Fluids to Dispersions Dr. Dmitri Kopeliovich Surfactant (surface active agent,detergent) is a substance reducing the interfacial energy of the solution in a contact with other phases. Surfactants promote dispersion of various phases: emulsification of oils (liquid phase), suspension of solid residuals (solid phase) in the alkaline cleaners and foaming (gaseous phase). text/html 2012-01-12T09:48:46-05:00 http://www.substech.com/dokuwiki/doku.php?id=alkaline_cleaning&rev=1326379726&do=diff1326379726 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Alkaline cleaning is a Surface preparation operation utilizing an immersion of the workpiece into an alkaline aqueous solution (or spraying of the solution on the workpiece) where the contaminants such as mineral oils and greases, vegetable oils, animal fats, Cutting fluids (coolants), residual soils, metal chips, dust, etc. are removed from the workpiece surface … text/html 2012-01-07T10:22:00-05:00 http://www.substech.com/dokuwiki/doku.php?id=steel_strip_processing&rev=1325949720&do=diff1325949720 Discuss the article and ask questions in our Materials Forum to Metals to Metal forming technologies Dr. Dmitri Kopeliovich Steel strips are commonly manufactured of continuously cast slabs. Coiled steel strips have the thickness (gauge) up to 0.2” (5 mm). The strips are supplied in different conditions: text/html 2012-01-07T10:15:43-05:00 http://www.substech.com/dokuwiki/doku.php?id=enhancement_of_adhesion&rev=1325949343&do=diff1325949343 Discuss the article and ask questions in our Materials Forum to Polymers to Paints Dr. Dmitri Kopeliovich Adhesion of a coating (paint, adhesive) to the substrate is a critical property determining its quality, durability and aesthetic properties. Strong adhesion is achieved by a combination of the surface treatment including cleaning (degreasing), mechanical or chemical roughening and increasing the substrate wettability. text/html 2012-01-07T10:14:44-05:00 http://www.substech.com/dokuwiki/doku.php?id=10_most_popular_articles_in_the_last_month&rev=1325949284&do=diff1325949284 December 2011 * Iron-carbon phase diagram * Hydraulic oils * Shore (Durometer) hardness test * Nickel electroplating * Metals crystal structure * Tensile test and Stress-Strain Diagram * Effect of alloying elements on steel properties text/html 2012-01-07T10:13:06-05:00 http://www.substech.com/dokuwiki/doku.php?id=full_index_of_articles_on_metals&rev=1325949186&do=diff1325949186 back to Contents * Fundamentals of metals * Metals crystal structure * Solid solutions * Diffusion in alloys * Grain structure * Imperfections of crystal structure * Crystallization * Basic processes in metals * Solidification * Phase transformations and phase diagrams * Microsegregation * Basic principles of heat treatment * Spinodal decomposition * Plastic deformation text/html 2012-01-07T10:12:23-05:00 http://www.substech.com/dokuwiki/doku.php?id=thermal_spraying&rev=1325949143&do=diff1325949143 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Thermal spraying is a method of deposition of a metal atomized at high temperature and delivered to the substrate surface in a high velocity gas stream. text/html 2012-01-07T10:12:02-05:00 http://www.substech.com/dokuwiki/doku.php?id=vapor_deposition&rev=1325949122&do=diff1325949122 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich There are two basic vapor deposition processes: * Physical Vapor Deposition (PVD) * Chemical Vapor Deposition (CVD) text/html 2012-01-07T10:11:21-05:00 http://www.substech.com/dokuwiki/doku.php?id=diamond-like_carbon&rev=1325949081&do=diff1325949081 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Structure of Diamond-Like Carbon (DLC) * Techniques of deposition of Diamond-Like Carbon (DLC) * Characteristics of Diamond-Like Carbon (DLC) * Applications of Diamond-Like Carbon (DLC) text/html 2012-01-07T10:10:56-05:00 http://www.substech.com/dokuwiki/doku.php?id=anti-stiction_coatings_for_mems&rev=1325949056&do=diff1325949056 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Microelectromechanical systems (MEMS) * Polycrystalline silicon for MEMS * Surface treatment of MEMS Microelectromechanical systems (MEMS) Microelectromechanical systems (MEMS) are devices combining very small mechanisms (up to 1mm/0.04”) with electronic integrated circuits. MEMS are assembled from mechanical components with the sizes 1-100μm (0.00004… text/html 2012-01-07T10:10:33-05:00 http://www.substech.com/dokuwiki/doku.php?id=phosphate_coating&rev=1325949033&do=diff1325949033 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Phosphate coating (phosphating) is a conversion coating consisting of an insoluble crystalline metal-phosphate salt formed in a chemical reaction between the substrate metal and a phosphoric acid solution containing ions of metals (zinc, iron or magnesium). Conversion coating is a film of a chemical compound formed in the reaction of the substrate substance wi… text/html 2012-01-07T10:10:08-05:00 http://www.substech.com/dokuwiki/doku.php?id=adaptive_tribological_coatings&rev=1325949008&do=diff1325949008 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Adaptive tribological coatings - description * Design of adaptive tribological coatings * Examples of adaptive tribological coatings text/html 2012-01-07T10:09:46-05:00 http://www.substech.com/dokuwiki/doku.php?id=black_copper_oxide_coating&rev=1325948986&do=diff1325948986 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Black copper oxide is a conversion coating of cupric oxide (CuO) formed on the surface of a copper alloy as a result of a chemical reaction of copper atoms with an oxidizing agent (air, salts). Conversion coating is a film of a chemical compound formed in the reaction of the substrate substance with another substance. This reaction distinguishes conversion coa… text/html 2012-01-07T10:09:27-05:00 http://www.substech.com/dokuwiki/doku.php?id=black_oxide_coating&rev=1325948967&do=diff1325948967 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Black oxide is a conversion oxide coating formed on the metal surface as a result of a chemical reaction of the metal atoms with an oxidizing agent (air, aqueous solution, molten salts). Conversion coating is a film of a chemical compound formed in the reaction of the substrate substance with another substance. This reaction distinguishes conversion coating fr… text/html 2012-01-07T10:09:03-05:00 http://www.substech.com/dokuwiki/doku.php?id=anodizing&rev=1325948943&do=diff1325948943 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Anodizing is an electrochemical process of growing conversion oxide coating as a result of oxidation of an anodically connected metal in an acidic electrolyte solution. Conversion coating is a film of a chemical compound formed in the reaction of the substrate substance with another substance. This reaction distinguishes conversion coating from a conventional … text/html 2012-01-07T10:08:31-05:00 http://www.substech.com/dokuwiki/doku.php?id=copper_plating&rev=1325948911&do=diff1325948911 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Copper plating is a process of copper deposition over a part immersed into an electrolyte solution and used as a cathode, when the copper anode is being dissolved into the electrolyte in form of the copper ions traveling through the solution and depositing on the cathode surface. Phosphorized copper (0.04-0.08% P)is recommended for the anodes in [Copper plating#A… text/html 2012-01-07T10:08:06-05:00 http://www.substech.com/dokuwiki/doku.php?id=silver_plating&rev=1325948886&do=diff1325948886 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Characteristics of silver * Silver strike * Cyanide silver plating * Non-cyanide silver plating * Properties of some silver alloys text/html 2012-01-07T10:07:35-05:00 http://www.substech.com/dokuwiki/doku.php?id=tin_alloy_electroplating&rev=1325948855&do=diff1325948855 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Characteristics of tin * Applications of electroplated tin alloys * Tin alloys used for electroplating * Tin alloy electroplating in fluoborate solutions * Tin alloy electroplating in methane sulfonic solutions * Tin electroplating in sulfate solutions * Tin electroplating in stannate solutions text/html 2012-01-07T10:07:06-05:00 http://www.substech.com/dokuwiki/doku.php?id=decorative_chromium_electroplating&rev=1325948826&do=diff1325948826 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Characteristics of chromium * Characteristics and applications of decorative chromium * Structure of decorative chromium deposition * Decorative electroplating with hexavalent chromium * Operating conditions of hexavalent chromium electroplating process * Trivalent chromium electroplating text/html 2012-01-07T10:06:33-05:00 http://www.substech.com/dokuwiki/doku.php?id=hard_chromium_electroplating&rev=1325948793&do=diff1325948793 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Characteristics of chromium * Characteristics and applications of hard chromium * Chemistry of hard chromium electroplating * Conventional hard chromium plating process * Hard chromium plating in fluoride bath * Operating conditions of hard chromium electroplating process * Problems and troubleshooting of hard chromium elctroplating text/html 2012-01-07T10:06:04-05:00 http://www.substech.com/dokuwiki/doku.php?id=electrolytic_co-deposition&rev=1325948764&do=diff1325948764 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich Electrolytic co-deposition is an Electroplating method of incorporation of non-metallic particles into metallic coatings obtained from electrolytes containing the particles in a suspended state. The second phase particles dispersed within the metal base form a metal matrix composite, properties of which may be significantly different from those of the pure metal… text/html 2012-01-07T10:05:32-05:00 http://www.substech.com/dokuwiki/doku.php?id=nickel_electroplating&rev=1325948732&do=diff1325948732 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich * Properties of nickel coatings * Basics of nickel electroplating * Nickel coating thickness * Problems and troubleshooting * Watts nickel plating solutions * Nickel sulfamate solutions * All-Chloride solutions * Sulfate-Chloride solutions * Fluoborate solutions * Hard nickel solutions text/html 2012-01-07T10:05:07-05:00 http://www.substech.com/dokuwiki/doku.php?id=diffusion_layer&rev=1325948707&do=diff1325948707 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich As Electroplating process proceeds the positively charged ions (of Metals or Hydrogen) are formed at the anode surface, transferred to the cathode and deposit on its surface when the negatively charged ions move toward the anode where they discharge. Such ion transfer process results in formation of thin electrolyte regions (diffusion layers) adjacent to the el… text/html 2012-01-07T10:04:46-05:00 http://www.substech.com/dokuwiki/doku.php?id=electroplating_alloys&rev=1325948686&do=diff1325948686 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich An alloy coating may be obtained by a co-deposition of the alloy constituents from the electrolyte containing their ions. Deposited alloys may possess properties and combination of properties, which ate not achievable in the coatings of pure metals. Electroplating allows to prepare alloys, which can not be produced by melting. Some metals may be deposited… text/html 2012-01-07T10:04:24-05:00 http://www.substech.com/dokuwiki/doku.php?id=electroplating&rev=1325948664&do=diff1325948664 Discuss the article and ask questions in our Materials Forum to Metals to Coating technologies Dr. Dmitri Kopeliovich [electroplating.png] Electroplating is a process of coating deposition on a part, immersed into an electrolyte solution and used as a cathode, when the anode is made of the depositing material, which is dissolved into the solution in form of the metal ions, traveling through the solution and depositing on the cathode surface.