Transcript Slide 1
LASER HARDENING • For small, large, surfaces: Locomotive cylinders • Close control of process possible, low distortion, can reach inaccessible regions, • Capital Cost high, but depth of 2.5 mm • Apart from carburizing and Nitriding, • CYANIDING • BORONIZING • CARBONITRIDING HEAT TREATMENT FURNACES • • • • • Batch Continuous Salt bath Fluidized Beds Induction heaters PROTECTION BY METALLIC COATINGS Protection: 1. Direct- by an unbroken film of corrosion-resistant metal covering the article. Eg: tin coatings on steel. 2. Sacrificial- metallic film becomes anodic and dissolves in preference to cathodic surface beneath. Methods: Electroplating, dipping into a bath of molten metal, spraying/volatilizing the protective metal onto the surface, Mechanical Cladding. Laminated Object Manufacturing Profiles of object cross sections are cut from paper or other web material using a laser. The paper is unwound from a feed roll onto the stack and first bonded to the previous layer using a heated roller which melts a plastic coating on the bottom side of the paper. The profiles are then traced by an optics system that is mounted to an X-Y stage. • After cutting of the layer is complete, excess paper is cut away to separate the layer from the web. Waste paper is wound on a take-up roll. The method is selfsupporting for overhangs and undercuts. Areas of cross sections which are to be removed in the final object are heavily cross-hatched with the laser to facilitate removal. It can be time consuming to remove extra material for some geometries • Market segments ranging from concept modeling to very large objects for architectural applications Principle of Ion Plating • MIT Technology Insider publish works on researchprincipally in microstructural design, with emphasis on the microstructure-property relationship in engineered materials. • One area of ongoing research is “grain boundary engineering,” which allows traditional metals and alloys to be dramatically improved in terms of cracking, creep, corrosion, and electro-migration resistance, often by an order of magnitude. These remarkable property enhancements are possible through tailoring the grain boundary network, promoting the development of grain boundaries with “special” crystallography and properties. • Studies on the development of these special boundary networks, the connectivity and percolation behavior of the grain boundary network, and the mechanical properties of these highly engineered materials. • Another area of research is nanocrystalline and amorphous materials. For these unique materials, conventional knowledge of the structure-property relationship breaks down and new physics discovered to explain their unique properties. The traditional as well as modern methods (such as nanoindentation) used to probe the microstructureproperty relationships of these materials. Of particular interest is the transition from a nanocrystalline to an amorphous structure (which occurs at grain sizes near ~2 nm) and the manner in which properties change through this regime. • scanning electron microscopy and Energy Dispersive X-ray Microanalysis (EDX). • Eg: 13A plug- List of Parts 1- Fuse Holder 2- Cover Screw 3- Earth Pin 4- Wire fixing screw 5- Live and Neutral Pins 6- Fuse holder rivet CLADDING • Mainly in the manufacture of clad sheets- employed prior to the final manufacturing stages of a component • Base metal sandwiched between the pieces of the coating metal, sandwich then rolled to the required thickness • In some, film of protective metal sprayed onto the base surface & then rolled. • ALCLAD- Duralumin coated with aluminium (0.01 mm thick) • MS clad with SS • But, damage to protective skin during fabrication CERAMICS earthenware, stoneware, porcelain • , Frederick Carlton Ball (1911-1992) was a prize fighter who went by the name "California Gene Tunney". • Teacher at California College of Arts and Crafts, Southern Illinois University, the University of Puget Sound, Mills College, Oakland and the University of Southern California, • Wrote book: 'Decorating Pottery with Clay, Slip and Glaze'