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Yf=Kεn1+nε=lnt0tfVolume of cylinder πr2 hTrue Stress = Yf=KεnAverage Flow Stress = Yf=Kεn1+nFlow stress= KεnTrue Strain ε=lnt0tPacking factor = bulk density / true densityPorosity=1-packing factorQd= 0.5π2D2NdcsinAcosAQb= pπDdc3sin2A12ηLQx=Qd?Qb Qx=Ksp TRS=1.5 FL/(wt2)Ks= πDd4128ηLdGF= v2Rg2πrN=linear speed Flow rate=Velocity*cross sectional areav12=v02+2gh Chvorinov rule=TTS =CmVAnArea of a cyclinder=2πrh+2πr2Volume of cylinder=πr2htan A=(pitch/πDIn a tensile test, two pairs of values of stress and strain were measured for the specimen metal after it had yielded: (1) true stress = 217 MPa and true strain = 0.35, and (2) true stress = 259 MPa and true strain = 0.68. The same metal is now tested in a compression test in which the starting height of the specimen = 62.5 mm and its diameter = 25 mm. Assuming that the cross section increases uniformly, calculate the force that would be required to compress the specimen to 57.5 mm If the machine is capable of applying 1,000,000 N of force, calculate the maximum amount of compression that the specimen experiences (i.e., final length) (bonus 7.5 points)Consider an extruder in which the barrel diameter = 4.75 in and length = 12 ft. The extruder screw rotates at 60 rev/min; it has channel depth = 0.38 in and flight angle = 18?. The plastic melt has a shear viscosity = 130 x 104 lbsec/in2. Determine: Qmax and pmax; the shape factor Ks for a circular die opening in which Dd = 0.3 in and Ld = 0.8 in; the values of Q and p at the operating point. The mining industries are considered part of_____________ industry classifications.Four categories of engineering materials that are used in the manufacturing processes are: Metals with alloys, plastics, ___________ , ______________ .Thermoplastic polymers might be processed through various heating and cooling cycles( )True( )FalseStrain hardening exponent is theoretically assumed to be 0 in the hot working. ( )True( )FalseDimensional consistency improves in hot working as compared to cold working ( )True( )FalsePrimary material in glass is Zinc(b) BauxiteSilicon(d)FiberTo alloy with copper to form brass, zinc is used as alloying material. ( )True( )FalseLead has high strength-weight ratio as compared to most of other metals.( )True( )FalseGlass has amorphous structure. ( )True( )FalseA three point rupture test might be used for determining the strength of ductile materials( )True( )FalseEutectic alloys have usually a multiple melting temperature. ( )True( )FalseUnilateral tolerance allows only positive deviation from the nominal dimension. ( )True( )FalseDie casting operations are associated with worse surface finish as compared to other casting operations.( )True( )FalsePoor surface finish usually leads to higher friction. ( )True( )FalseCeramics have poor thermal conductivity as compared to metals.( )True( )FalseRoughness and waviness are usually defined in term of resolution of spacing of actual surface from ideal surface ( )True( )FalseThe swelling of the plastic upon exiting the die is an example of the viscoelasticity.( )True( )FalseOne of the functions of the screen pack is to increase the rate of flow of the plastic in the plastic extrusion process.( )True( )FalseWhich one is not a finishing operation(a)Honing(b)Lapping(c)Polishing`(d)DrillingPattern generally stays within the mold during casting process. ( )True( )FalseUsing expendable molds in general increase rate of production. ( )True( )FalseParting line is a feature that belongs to open mold casting. ( )True( )FalseMetal supports of various designs used to hold the core in place in the sand mold are called _______.Which one is not the required property of the sand in the sand casting processCollapsibility(c)StrengthReusability(d)ProductivityPenetration is a defect observed in the die casting process.( )True( )FalseIn general, viscosity decreases with increasing temperature.( )True( )FalseSand is an essential part of the mold for the sand casting processes.( )True( )FalseThe coefficient of the exponential term in Chvorinov’s rule is usually assumed to be.(a)1(b)3(c)2(d)4A mold has a downsprue of length = 1 m. The crosssectional area at the bottom of the sprue is 0.05 m2. The sprue leads into a horizontal runner which feeds the mold cavity, whose volume =1 m3. A molten metal is poured down the sprue so that the cavity can be filled in 4 seconds. Determine the initial velocity of the molten metal that would be required at the top of the downsprue the volume rate of flow at the bottom of the downsprue, andthe required velocity of the molten metal at the bottom of the downsprue (d) How would the results change for part (a) if you consider the friction effects (air and mold walls friction). Comment qualitatively (e.g. increase decrease, or stays the same) Ignore all friction effects for parts (a), (b), and (c), and assume g to be 9.81 m/sec2A true centrifugal casting operation is performed in a horizontal configuration to make cast iron pipe sections. The sections will have a length =1 meter, outside diameter = 25 cm, and wall thickness = 1 cm. If the rotational speed of the pipe = 1000 rev/min, determine the Gfactor. Is the operation likely to be successful considering that the gravitational factor for successful operation is usually between 60 and 80? Assume g assume to be 9.81 m/sec2What would be the pressure on the walls of the die, if the density of the cast metal is 5.61 gr/cm3? In a certain pressing operation, the metallic powder fed into the open die has a packing factor of 0.5. The pressing operation reduces the powders to 3/5 of their starting volume. In the subsequent sintering operation, shrinkage amounts to 10% on a volume basis. Given that these are the only factors that affect the structure of the finished part, a.determine its final porosity.If the corresponding bulk metal has the density of 7.65 gr/cm3, what would be the density of the product obtained at the end of the series of powder metallurgy related processes?A diskshaped part is to be cast out of aluminum. The diameter of the disk = 500 mm and its thickness = 20 mm. It took 155 seconds to solidify. Assuming the same mold constant applies, what would be the time required for solidification of the casting of aluminum sphere that has a radius of 300 mm.Is the sphere shape suitable for the riser design, please discuss. ................
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