Coh3 chemical name

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1. XRD techniques used for stress measurements (basics, principles, advantages, disadvantages…) and examples of use in the Case of surface engineering. It´s uses Bragg´s Law =2dsenσ, is the elastic relation to Obtain stress value. _Advantages:-Non-destructive.-fast, simple.-can be done in situ.-high Accuracy._Disadvantages: It Is much more accurate for measuring large crystalline structures rather than Small ones._Examples:Sampling Of geological specimens. Material characterization.

2.Chemical vapor deposition (CVD), describe the Different experimental methods. Give examples. Advantages and disadvantages.Definition: Is a chemical process used to produce High-purity, high-performance solid materials. It is often used to produce thin Films. Source gas is introduced into a reaction chamber and energy is applied Through heat that results in the decomposition of the source gas and reaction Of the chemicals to form a film. ????????????4→????????+2????2????._Experimental Methods:-Atmospheric Pressure Chemical Vapour Deposition (APCVD).-Low Pressure Chemical Vapour Deposition (LPCVD).-Metalorganic Chemical vapor deposition (MOCVD)._Examples of materials: Silicon, carbon Fiber, carbon nanofiber, filaments, carbon nanotubes, SiO2, silicon-germanium, Tungsten, silicon carbide, silicon nitride._Advantages:High growth rates Possible,Can deposit materials which are hard to evaporate,Good reproducibility,Can Grow epitaxial films)._Disadvantages:High temperatures,Complex processes,Toxic And corrosive gases.

3. Describe what is painting coating, describe the Different experimental methods. Give examples. Advantages and disadvantages.It is a type of coating that is applied as a dry powder. It is one of the surface finishing techniques in common use today. It Was first used in Australia about 1967._It takes three successive steps: Surface preparation,application of a dry powder/heating of the workpiece,inspection._Examples Of applications:-Appliances: refrigerators,washer tops and lids.-Automotive: Wheels, bumpers, hubcaps._Advantages:Powder is generally less flammable than Liquid coating,No waste of coating (powder that does not adhere is collected),Low Operating cost._Disadvantages: Start-up costs,Color change difficulties

4. What is XPS? Advantages and limitations. Give examples concerning Engineering materials XPS measures the elemental composition, empirical Formula, chemical state and electronic state of elements. XPS spectra are Obtained by irradiating a material with a beam of X-rays while simultaneously Measuring the kinetic energy and number of atomic core electrons that escape From the top 1 to 10 mm._Advantages: It can probe down to core electrons (great Range of application).It is capable of detecting the difference in chemical State between samples.It is able to differentiate between oxidations states of Molecules._Limitations:Spectra take a long time to be obtained,It can provide a Limited amount of organic information.The smallest analytical area that it can Measure is 10 μm)._Examples:Polymers and Adhesives.Heterogeneous catalysis. Metallurgy.

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