Fig. 4 Pure copper Billet for Fig. 5 Pure aluminum Billet for micro extrusion micro extrusion
It should be noted that the grain size of the material can be varied by heat treatment process. The billets are exposed to heat treatment with different temperatures (5500C and 6500C) and working times to obtain different grain size. The original microstructure of copper and aluminum is shown in Fig. 6 and Fig 7. Fig. 6 Microstructure of Fig. 7 Microstructure of Original copper Original aluminum Fig. 8 Copper heat treated for Fig. 9 Copper heat treated for 6500C 5500C
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2.3 MEASUREMENT OF MICROHARDNESS
A microhardness measurement is done using the Mitutoyo micro hardness tester (load range 10 g to 2 Kg) for two samples. The measurements are taken at various radial locations on deformed pins to assess their work hardening. For the micro hardness test procedure, ASTM E-384 is followed to measure hardness value and the values are averaged. Sample preparation is necessary with a micro hardness test in order to provide a small enough specimen that can fit into the tester (Fig. 10).
Fig. 10 Copper samples prepared for micro hardness testing
2.4 MEASUREMENT OF SURFACE ROUGHNESS Surface roughness measurement is carried out using a portable surface roughness tester (Fig. 11). The sampling length is around 0.8 mm with a velocity of 0.5 mm/s. Table 2 gives the surface roughness values. It is noticed that the values are consistent across grain sizes.
Table 2 Average Surface roughness
Average Grain Size(µm) Average surface Roughness(Ra)
(µm)
38 0.50 ± 0.05
90 0.60 ± 0.07
136 0.72 ± 0.09
Fig. 11 Surface finish measurement using portable surface roughness tester 3 RESULTS AND
The Papanicolaou test in medical terms can also be known as or be called as the Pap smear, pap test, or smear test. It is a microscopic examination of cell .The purpose of this test is to perceive occurring of precancerous or existing cancerous cells in the opening uterus of the cervix. It also discerns asymmetry in the cells of the cervix (the bottom, narrow end of the uterus.)[1]
We use metals to construct all kinds of structures, from bridges to skyscrapers to elevators. The strength as well as durability of materials that are crafted out of metal make the materials ideal not only for construction but also for many other applications.
For the other material ASTM A216 Gr WCB same pressure of 16 Mpa is applied and the stress developed is approximately as similar to the connecting rod made with material of cast iron. Figure no. 9 indicates the maximum and minimum stress developed in connecting rod at small & big end. The equivalent stress maximum and minimum values are 71.347 MPa and 4.4955e-5 MPa respectively.
The surface morphology and the surface roughness of the untreated and treated PP samples were investigated by AFM. The Figure 1 represents the AFM images in a three dimensional view of untreated and treated samples in a time of 60s with various power rates. The scan size of all the images is 5×5 μm2. Evidently, the oxygen plasma treatment modified the surface morphology of the PP
Aluminum is a lightweight, silvery metal. The atomic weight of aluminum is 26.9815; the element melts at 660° C (1220° F), boils at 2467° C (4473° F), and has a specific gravity of 2.7. Aluminum is a strongly electropositive metal and extremely reactive. In contact with air, aluminum rapidly becomes covered with a tough, transparent layer of aluminum oxide that resists further corrosive action. For this reason, materials made of aluminum do not tarnish or rust. The metal reduces many other metallic compounds to their base metals. For example, when thermite (a mixture of powdered iron oxide and aluminum) is heated, the aluminum rapidly removes the oxygen from the iron; the heat of the reaction is sufficient to melt the iron. This phenomenon is used in the thermite process for welding iron .
Metal finishing is the critical part and step in preparing the metal for painting. It happens between the bumping stage when the metal is pried, hammered, pulled, and pushed into shape and the filling stage, when the small defects and details in metal finished surfaces are filled before being painted. Any type of finish is applied over your work weather the it be solvent, powder coated, or plastic it will have an index of reflection and ...
In today’s world, there are many people who feel the pull of continuing their education by going to college. There are many factors that affect this process, and can either make or break a student’s attempt at academic success. Some of the factors are commonsensical, and others may not be as obvious – especially for returning students who have been out of school for a long period of time. There are many tools available to help students of all backgrounds discover their strengths, weaknesses, skills, and learning styles, all of which will help them prepare for their school routine. One of these tools is the Smarter Measure Assessment, which is an online tool that uses simple questions to measure a student’s readiness for classes. Although
Standardized testing is not the best way to measure how well a teacher teaches or how much a student has learned. Schools throughout the United States put their main focus on standardized tests; these examinations put too much pressure on the teachers and students and cause traumatizing events. Standardized testing puts strain on teachers and students causing unhealthy occurrences, Common Core is thrown at teachers with no teaching on how to teach the new way which dampers testing scores for all students, and the American College Test determines whether a child gets into college or not based on what they have learned during high school. Standardized tests are disagreeable; tests should not determine ranking of people.
In order to perform the micro hardness test on the samples, they were first roughly polished using belt grinder. Then they were polished with the Emery papers as described in previous descriptions so as to obtain flat surfaces and to avoid anomalies in the results.
Aluminum is one of a number of soft metals that scientists call "poor" metals. It can be shaped and twisted into any form. It can be rolled into thick plates for armored tanks or into thin foil for chewing gum wrappers. It may be drawn into a wire or made into cans. Aluminum is a generally popular metal because it does not rust and it resists wear from weather and chemicals. (Bowman, 391) Aluminum is an element. Its atomic number is thirteen and its atomic weight is usually twenty-seven. Pure aluminum melts at 660.2ºC and boils at 2500ºC. Its density is 2.7 grams per cube centimeter. Aluminum is never found uncombined in nature. (Bowman, 391) Aluminum is a very useful metal that is light, easy to shape and can be strong. This makes aluminum one of the most used metals in the world, right behind iron and steel. (Geary, 185) In its pure state, aluminum is quite weak compared to the other metals. However, its strength can be greatly increased by adding small amounts of alloying elements, heat-treating, or cold working. Only a small percentage of aluminum is used in its pure form. It is made into such items as electrical conductors, jewelry, and decorative trim for alliances and cars. A combination of the three techniques has produced aluminum alloys that, pound for pound, are stronger than structural steel. Some common metals used in alloys for aluminum are copper, magnesium and zinc.(Walker, 31) The added elements give the aluminum strength and other properties. (Newmark, 41) Aluminum is one of the lightest metals. It weighs about 168.5 pounds per cubic foot, about a third as much as steel which weighs 487 pounds per cubic foot. (Neely, 214) As a result, aluminum has replaced steel for many uses. For example, some ...
The notch depth and tip radius is very important as some materials are more sensitive toward notches. Notches in the materials serve as stress concentration zones.
Forging, one of many manufacturing process, is where metal is pressed, pounded or squeezed under great pressure into high strength parts known as forgings. The process begins with starting stock which is heated to its plastic deformation temperature, then upset between dies to the desired shape and size. It is important to note that the forging process is entirely different from the casting (or foundry) process, as metal used to make forged parts is never melted and poured (as in the casting process). During this hot forging process, coarse grain structure is broken up and replaced by finer grains. Mechanical properties are therefore improved through reduction of cast structure, voids and segregation. Forging also provides means for aligning
Aluminum is an element in the boron group with a symbol of Al, and an atomic number of 13. Aluminum is a very soft metal when pure but becomes strong and hard when alloyed, a malleable metal with a silvery gray color. Aluminum is a very reactive element so it is found in nature combined with other elements. Aluminum resists corrosion by the formation of a self-protecting oxide coating. Aluminum is the third most abundant element in the Earth’s crust, following oxygen and silicon. It makes up approximately 8% by weight of the Earth’s surface. Although this is evident, it is also apparent that aluminum is never found by itself in nature. All of the earth’s aluminum has combined with other elements to form compounds and in order to create new aluminum products; it has to be taken out of that specific compound. Aluminum does not rust like other elements, therefore it always remains strong and shiny, which means reused aluminum is almost identical to a brand new piece of metal. An electrochemical process creates aluminum. An electrochemical process is “the direct process end use in which electricity is used to cause a chemical transformation” ( E.I.A. Government). Major uses of electrochemical processes occur in the aluminum industry in which alumina is reduced to molten aluminum metal and oxygen, where than the aluminum can be used into making several different materials. Electrochemical processes, although very useful, can have serious environmental consequences. To help reduce the consequences that the production of aluminum creates, the idea of aluminum recycling comes into play.
Metals possess many unique fundamental properties that make them an ideal material for use in a diverse range of applications. Many common place things know today are made from metals; bridges, utensils, vehicles of all modes of transport, contain some form of metal or metallic compound. Properties such as high tensile strength, high fracture toughness, malleability and availability are just some of the many advantages associated with metals. Metals, accompanied by their many compounds and alloys, similar properties, high and low corrosion levels, and affects, whether negative or positive, are a grand force to be reckoned with.
In summary, the rate of cooling from the austenite phase is the main determinant of final structure and properties.