...Molding Methods Molding process is used to create intricate metal components. The mold material used to make these “molds” could be either temporary or permanent. Temporary molds are made up of refractory sands and resins. The temporary mold has to be broken to retrieve the cast. Permanent molds are made of ferrous materials and are normally employed for casting low melting point materials but this process is too costly. Because of this conundrum, most of the foundry industry has its castings produced using temporary mold materials. Compared to permanent molds, the temporary sand molds can cast high melting point materials and larger parts, while permanent molds can produce small castings of better quality and dimensional accuracy. Sand casting uses temporary sand molds to form complex metal components that can be made of almost any alloy. Sand casting has a relatively lower production rate as each time the part solidifies, the mold has to be broken to retrieve the part. The sand casting process makes use of a furnace, metal, pattern, and sand mold. The metal is melted in the furnace, ladled, and then poured into the cavity of the...
Words: 1218 - Pages: 5
...LIQUID METAL EMBRITTLEMENT (LME) RAGHAV MOHAN Graduate Student M.S in Technical Entrepreneurship and Management University of Rochester INTRODUCTION Liquid metal embrittlement (LME) is a phenomenon of practical importance, where certain ductile metals experience drastic loss in tensile ductility or undergo brittle fracture when tested in the presence of specific liquid metals. Generally, a tensile stress or a residual stress is needed to induce embrittlement. Many mechanisms were proposed to explain the phenomenological characteristics of LME. The significance of liquid metal embrittlement is revealed by the practical observation of several structures experiencing ductility losses and cracking during hot dip galvanizing or during subsequent fabrication. Liquid metal embrittlement effects can be observed even in solid state, when one of the metals is brought close to its melting point (e.g. cadmium-coated parts operating at high temperature). This phenomenon is known as solid metal embrittlement. OBSERVATIONS OF LME Mechanical structures are typically a space frame fabricated from parallel large diameter tubes, called chords, cross braced by smaller diameter perpendicular and diagonal tubes(e.g. sign bridge structures over freeway) .After welding, the structure is hot dip galvanized. The hot dip galvanizing process consists of submerging the structure in a bath of molten zinc. This leaves a relatively uniform zinc coating over the entire structure upon...
Words: 2194 - Pages: 9
...Nickel is silvery-white in color. Nickel is the only one metal which creates confusion because copper and nickel both occurred in ores with green tint. It is also the most abundant element after iron. Manufacturing Process Nickel is extracted from the millerite, pyrrhotite and nickel sulphides pentlandite, which have about 1% of nickel. Nickel sulphide are found deep underground, so they are expensive in extraction. The Mond(Carbonyl) is the major process to treat nickel sulphide. Firstly, the sulphide is treated with hydrogen and served into a volatilization kiln. Carbon monoxide gas is passed at 60C° to produce nickel carbonyl gas that further decompose on the surface of pre-heated pellets that transfer through a heat chamber until it get the desired size. This process can used at high temperature to form nickel powder. Lateritic ores are usually produced by pyro-metallic methods because of its high iron content. These ores have moisture content therefore they required drying in rotary kiln furnace. Further the nickel oxide is produced which is reduced by using electric furnace that produce nickel metal. Mechanical...
Words: 691 - Pages: 3
...The element barium, shown using the symbol Ba, is a soft alkaline earth metal. It is located in the second group and fifth period on the periodic table, and has an atomic number of 56. This element’s atomic mass is 137.327 u ± 0.007 u. The first known account of this element was in the early 1600’s, in Bologna, Italy, when alchemists of the time noted the discovery of smooth pebbles located near volcanic rock. These stones glowed for an extended period of time after exposure to light, inspiring questions as to what made them do this. In 1774, Carl Wilhelm Scheele concluded that barite, a white or colorless mineral, was formed with an unknown element; however he was only able to isolate a compound called barium oxide. Other chemists and scientists around the world also made attempts in the following years to isolate this new element, but without success. Sir Humphry Davy, who isolated five new elements before his death, was the first to fully isolate the element through the use of electrolysis of molten baryta in 1808. Barium is a highly reactive element, and is never found in its pure state in nature. When a reaction occurs with oxygen, it produces...
Words: 911 - Pages: 4
...The materials, equipment, and processes used in the metal stamping industry have proven to be less costly than the original methods of forming metals and alloys into definite shapes. Metal stamping is the method of bending, clipping, and molding sheet metal or coil metal by stamping and pressing the material into the desired forms. The shaped metal is plated with nickel, tin, or some other metallic elements to protect it from corrosion. The most commonly used metals are steel, aluminum, zinc, and nickel. They are low cost, strong, durable, hard to break, portable, and non-toxic. The precision machining industry in North America has been on the decline due to two factors: the chronic inflation in the price of raw materials and the transportation of same, and a high level of outsourcing to China and India. Outsourcing hasn't struck the metal stamping industry as profoundly thanks to the proximity of the Great Lakes, around which it is concentrated. The fire-and-brimstone...
Words: 721 - Pages: 3
...studying the components of Durkheim water using flame spectroscopy, the chemists noticed an emission that they had never seen before. This element, soon to be named cesium, was the first element to be found using spectroscopy. Even though they were first credited with the discovery of cesium, they were unable to produce a sample of the metal. Carl Theodor Setterberg at the University of Bonn was later able to posses it by electrolysis of molten caesium (caesium)....
Words: 679 - Pages: 3
...Objective: To demonstrate the way crystals grow and how they affect the behavior of material. A comparison can also be made between the growth of the crystals in metals and non-metals. Equipment: Hot plates, glass plates, beakers, glass rods, scale to weigh out the salt, graduated flask for water, furnace, crucibles, sand, tongs, safety glasses and gloves. Starting materials: Epsom salts, water, 50% Aluminum - 50% Copper alloy (previously alloyed). Safety: Whenever you are dealing with hot liquids, there is the potential for burns and spills. Protect yourself from the possible risks, especially around the hot metal. Make sure you know where any potential spillage will go and place something in the way to protect yourself. In part ‘B’ be especially careful of the hot metal. Remember, it will still be very hot, even when it has changed back into a solid. Procedure: Part A: A supersaturated solution of salt will separate out into crystals on cooling. The size of the crystals is a function of the rate of cooling, the amount of impurities present and the degree of supersaturation (concentration of salt present in the solution). 1. Dissolve 25 grams of Epsom salts in 25 ml of water. Heat the water until all the salt dissolves, but keep the water below the boiling point. If all the salt will not dissolve, add water in small quantities until it does. Pour some of the solution onto a clean glass plate so as to form a thin film and watch it solidify. If it solidifies too rapidly...
Words: 841 - Pages: 4
...Pasagui, Lhexter Bryan C. ME-4103 11-51269 Assignment #2 1. For me, forging is the process of shaping molten metals using specific forces while smithy is the location or the place where forging occur. 2. Open fire produces more heat than stock fire. 3. In chamber furnace, reheating of materials are held, it is mostly used in forging. While in twin chamber furnace reheating of circular rods occur. And in box furnace, heating of flat surfaces. 4. With drawing, tensile strength rises and surface finished is achieved. 5. Die pressure decreases because the die exit’s size increases. 6. As the back tension increases the die pressure decreases. 7. In direct extrusion, extruded products go in different locations. In indirect extrusion, the...
Words: 579 - Pages: 3
...Homemade Batteries Homemade batteries are a popular subject with my readers. Making electricity from things you find around the house is a fun project. There are lots of easy ways to make homemade batteries. Basically, any two different kinds of metal can be placed in a conducting solution and you get a battery. Familiar homemade batteries include sticking copper and zinc strips into a lemon or a potato to make a battery. One quick battery is made from a soda can, the soda from the can, and some copper. Click on image for a larger picture The photo above shows a battery made by placing a strip of copper and a strip of aluminum into a glass of Coca-Cola (I used the sugar-free cherry flavored variety because that's what I found in the refrigerator). You can make the aluminum strip by cutting open the can. You will need some sandpaper to sand off the paint and plastic coating from the aluminum before using it. Or you can get strips of aluminum already free of coatings from a hardware store, or from our catalog. You can get copper flashing from a hardware store and cut out a strip of it, or you can use a bunch of copper wire (the more surface area exposed to the liquid, the more electrical current is produced). Or, as before, you can get pre-cut strips from our catalog. The aluminum-copper-coke battery will produce about three quarters of a volt. Click on image for a larger picture Using a zinc strip instead of the aluminum produces a little over a volt in the copper-zinc-coke...
Words: 2668 - Pages: 11
... When molten alloys are cast, solidification starts at the walls of the mold as it is being cooled. The solidification of the alloy takes place not at a specific temperature but over a range of temperatures. While the alloy in the this range, it has a pasty form that consist of solid, tree-like structures called dendrites (meaning tree-like) and metal. The formation of Stable Nuclei in Liquid Metals: The two main mechanism by which the nucleation of solid particles in liquid metal occurs are homogeneous nucleation and heterogeneous nucleation. Homogeneous Nucleation in a liquid melt occurs when the metal itself provides the atoms needed to form nuclei. When a pre liquid metal is cooled below its equilibrium freezing temperature to a sufficient degree, many homogeneous nuclei are created by slow-moving atoms bonding together. For a nucleus to be stable so that it can grow into a crystal, it must reach a critical size. A cluster of atoms bonded together that is less than a critical size is called an embryo and one that is larger than the critical size is called a nucleus. Embryos: Small particles of a new phase formed by a phase (i. e. solidification) that are not of critical size and that can resolve. Nucle: Small particles of a new phase formed by a phase change (e . i . solidification) that can grow until the phase change is complete. Homogeneous Nucleation: The formation of small regions of a new solid phase ( called nuclei) in a pure metal that can grow...
Words: 2574 - Pages: 11
...paper, leaving the residue on the impermeable substance/filtrating medium and the filtrate to pass through. | Dissolved solids in liquids Evaporation | If the liquid in the mixture is more volatile (boiling point is lower) than the soluble solid, the soluble solid will remain while the liquid evaporates. The procedure employs the use of an evaporating dish and a Bunsen burner. | Crystallisation | Another method of dissolved solids from a liquid mixture (solution)The impure salt is dissolved in water at a high temperature to create a concentrated solution.The mixture is then cooled and the salt crystallises, leaving the impurity in the solution.This crystallised slat contains much less of the impurity than before. The salt can then be filtered and dried.Sugar cane industry. | Assess separation techniques for their suitability in separating examples of earth materials, identifying the differences in properties which enable these separations Yes, fractional distillation can separate a mixture of oxygen and nitrogen because they have similar (but not the same) boiling points. Could filtration successfully separate sand from a sand-salt mixture? No. Without water the salts in the sand and salt mixture will not separate out via filtration because filtration requires an insoluble solid plus a liquid mixture, which in this case would be salt + water Describe situations in which gravimetric analysis supplies useful data for chemists and other scientists * the process...
Words: 6530 - Pages: 27
...lighter, more flexible, and less expensive. Aluminium wire in power grid applications was very successful and is still used today. Wiring in homes and buildings is another matter. In the '60s when the price of copper skyrocketed, aluminum wire was manufactured in sizes small enough to be used in homes. Aluminium wire requires a larger wire gauge than copper to carry the same current. For example, a standard 15 A branch circuit wired with No. 14 gauge copper requires No. 12 gauge aluminum. When first used in branch circuit wiring, aluminum wire was not installed any differently than copper, and many of these connections failed due to bad connection techniques and dissimilar metals. These connection failures generated heat under electrical load and resulted in overheated connections. Most metals oxidize when exposed to air. Aluminium oxide is an electrical insulator. The aluminum in a slightly loose conenction oxidizes and over time will fail. In the late 1960s, the CU/AL specification was...
Words: 5418 - Pages: 22
...U.S. is the second largest importer of base metals after China (Indexmundi.com, 2013). It is the third largest exporter of base metals after China and Germany (Indexmundi.com, 2013). We can make the assumption that this makes U.S. a net importer of base metals. Base metals are mainly used as (a) input by manufactures producing consumer goods and (b) for infrastructure projects. They themselves are not demanded directly by consumers. If global prices of base metals were to go up, in theory, the U.S. will first see an impact on the "input" side of the economy (figure 7). Production costs will go up and producers will pass this one to the end consumer (P1 to P2). Raw material price increase will shock the supply to shift left (AS1 to AS2) and negative output gap increases (Y1-Y* to Y2-Y*). With increased prices, aggregate demand will go down. The AD curve will shift down (AD1 to AD2). This will result in a fall of real GDP, increase in the negative output gap (Y3-Y*) and prices may fall somewhat to P3. If there is no supply side change, typically, increases in the negative output gap will cause inflation to go down. The only time inflation increases with increasing negative output gap is when the AS curve shifts left and AD shifts down as well. To substantiate this, the following data has been presented as below, with main emphasis in the 2007-2008 periods: 1. Figure 8a (Research.stlouisfed.org, 2013 and Databank.worldbank.org, 2013) shows that from around 2008 the U...
Words: 674 - Pages: 3
...Hace su aparición durante el Siglo VIII que recoge la tradición de los pueblos sirio-persas, aunque introduce un aplicación, del esmalte blanco (mal llamado barniz blanco opaco), empleando dióxido de estaño. La característica más sobresaliente de la cerámica árabe, se puede concretar en que toda ella presenta un reflejo metálico, el cual se conseguía mediante una mezcla de cinabrio, sulfato de cobre, óxido de hiero, azufre y plata, actuando, en ocasiones el vinagre como disolvente. Esta aplicación siempre se cocía a más baja temperatura que el esmalte de base compuesto por: sulfuro de plomo, dióxido de estaño, sílice y arena con detalles en azul cobalto. Una característica de la cerámica primitiva es que es una monococción. Las formas de las vasijas de uso diario eran sencillas y estaban decoradas, principalmente, con motivos geométricos. Los colores predominantes son, marrones-violáceos, conseguidos a partir del óxido de manganeso y los verdes, con el óxido de cobre. También se usaban como elemento decorativo las incisiones y perforaciones. El mayor impulso se fraguó en la época del califato de Córdoba. Aplicaron el barniz plúmbeo o vidriado, al mismo tiempo que lo coloreaban usando la mezcla de óxidos. Se inicia la técnica de la "cuerda seca", que consiste en aplicar unas finas líneas de materia grasa con el fin de que no se mezclen colores colindantes. La fabricación de ladrillos también experimento un gran avance. Los centros más importantes de producción cerámica...
Words: 268 - Pages: 2
...into the sediments. For each of the three lakes, sediment samples are taken from ten different locations within each of the lakes. The sediment samples are examined for five particular metals. These are Nickel (Ni), Copper (Cu), Zinc (Zn), Arsenic (As) and Lead (Pb). The purpose of this report is to find out what the level of each metal contaminant in each of the lakes and compare the level against Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2000 Volume 1 (ANZECC, 2000). Also to find the possible source of each metal tested. Results Table 1. Metals concentration in sediments from Knighton Lake, University of Waikato, 2000 | Ni | Cu | Zn | As | Pb | minimum (ppm) | 8 | 39 | 416 | 15 | 40 | Maximum (ppm) | 13 | 79 | 1515 | 25 | 170 | Mean (ppm) | 11 | 62 | 892 | 21. | 88 | standard Deviation | 1.65 | 12.32 | 317.93 | 3.27 | 44.23 | | | | | | | The Knighton Lake results when compared against the guidelines showed that the concentration of nickel and copper are below the trigger value and therefore are at an acceptable level. The results for the arsenic and lead are just above the trigger level. The zinc level however is at a very high level, its 484.8 ppm higher than the ISQH-High value in the ANZECC, 2000. Table 2. Metals concentration in sediments from Oranga Lake, University of Waikato, 2000 | Ni | Cu | Zn | As | Pb | minimum (ppm) | 10 | 68 | 1097 | 14 | 17 | Maximum (ppm) | 17 | 134 | 1895 | 29...
Words: 1107 - Pages: 5
