Database Manufacturig AGGIORNATO PDF

1. Which statement/statements is/are correct about the built-up edge on a cutting tool: - It alters the rake angle; - It alters workpiece surface roughness; - None of the other answers; - It cannot be avoided during a cutting operation; - It does not alter the rake angl...

1. Which statement/statements is/are correct about the built-up edge on a cutting tool: - It alters the rake angle; - It alters workpiece surface roughness; - None of the other answers; - It cannot be avoided during a cutting operation; - It does not alter the rake angle; 2. Which statement/statements is/are not correct about wire drawing; - Requires lubrication - It is performed at high temperature - Under ideal plastic behavior, maximum drawing reduction depends on strain hardening exponent - Drawing stress reduces at increasing drawing ratio - Center burst is a defect that may appear 3. Which statement/statements is/are correct when the rake angle reduces in orthogonal cutting - Shear area increases; - Shear angle increases; - Shear area reduces; - Chip thickness is unchanged; - Cutting force reduces; - Shear angle reduces; 4. Which statement/statements is/are correct about flat rolling - Thick laminates require small rolls; - The presence of an external front tension moves the neutral planetowards the exit region; (slide 36 cap.06 Rolling) - The presence of an external back tension moves the neutral plane towards the entry region; (slide 36 cap.06 Rolling) - None of the other answers; - The roll bite condition is influenced by the roll diameter; (slide 18 cap.06 Rolling) 5. Which of the following parameter/parameters is/are in the equation to calculate the chip thickness ratio (in an orthogonal cutting model)? - Clearance (of relief) angle; - Cutting speed; - Shear angle; - Feed rate; - Solid (or cutting) angle; - Rake angle; 6. The ideal deformation in an extrusion process depends on - Extrusion stress; - Friction; - Plastic behavior of the metal part; - Extrusion force; - Die angle; - Only the initial (before extrusion) and the final areas (after extrusion) of the metal part; 7. In flat rolling, which statement/statements is/are correct regarding the speed of the laminate - The speed of the laminate reduces by moving from the entrance to the exit of the rolling mill; - The speed of the laminate increases from the entrance of the rolling mill to the neutral plane, but decreases from the neutral plane to the exit of the rolling mill; - None of the other answers is correct; - The speed of the laminate is maximum at the neutral plane; - At the neutral plane, the speed of the laminate is different from the peripheral speed of the rolls; - At the neutral plane, the peripheral speed of the rolls is lower than that of the laminate 8. Which statement/statements is/are correct about extrusion - It does not require lubrication; - Aluminum extruded parts are most common than other metal alloys; - It is mainly carried out at low temperatures; - Direct extrusion normally requires larger pressures than indirect extrusion; - In direct, pressure does not modify significantly for most of the process; - None of the other answers; 9. Reducing strain rate tends to have which one/ones of the following effects on flow n stress (σ=Kε ) and metal behavior during cold forming of metal - Decreases flow stress; - Modifies strength hardening exponent, n - Metal show a lower ductility; - Metal show a larger ductility; - Increases flow stress; - Modifies Young modulus; - Modifies strength coefficient, K 10. A linear (i.e. not curved) groove could be made with which of the following machine tools - Deep drawing machine - Broaching machine (DUBBIA, pacchetto slide 12) - Lathe - Milling machine - None of the other answers - Shaping machine (DUBBIA, pacchetto slide 12) - Drilling machine 11. Which of the following machining operation/operations commonly uses/use multiple-point cutting tools? - Sawing - Planing - Broaching - Milling - Turning - Drilling - Shaping 12. Which of the following process/processes is/are not chip removal operation - Rolling - Planing - Broaching - Thread rolling - Coining - Trimming 13. Which statement/statements is/are correct about upsetting - Upsetting pressure reduces with an increase of friction coefficient - Upsetting pressure is zero at the lateral side of the part - Upsetting pressure is zero at the middle of the part - None of the other answers is correct - The dies are commonly flat - Upsetting pressure decreases from the lateral side to the middle on the part 14. The maximum thickness reduction (i.e. draft) possible in a flat rolling operation depends strictly on which of the following parameter/parameters - None of the other answers - Friction coefficient between rolls and workpiece - Position of the neutral plane - Initial thickness of the laminate - Rotational speed of rolls 15. A roughing operation generally involves which one/ones of the following combination of cutting conditions (where v = cutting speed, f = feed and d=depth) - low v, f and d - high v, low f and d - none of the other answers is correct - low v, high f and d (Slide 12 cap 09-Theory of metal Machining) - high v, f and d 16. A shaping (i.e. performed with a shaper) operation during the cutting is described by which one/ones of the following statements: - a tool with multiple teeth moves linearly past a stationary workpart - a workpart moves linearly past a single point-tool - none of the other answers is correct - a workpart il fed linearly past a rotating cutting tool - a single point tool moves linearly past a stationary workpart (Slide 2 cap.13) 17. in a single step of wire drawing, the maximum drawing reduction of a metal WITH strain hardening (but NO friction, NO redundant work) depends directly on: - drawing force - strain hardening exponent of the hollomon equation (FORSE) - die angle - friction - drawing stress 18. In which manufacturing operation may locked and counterlocked dies be used? - Machining operations - Extrusion - Upsetting - Impression die forging - Rolling - Drawing 19. Which of the following operation/s is/are closely related to open-die forging? - Hobbing - Upsetting - Coining - Fullering - Cogging 20. Facing operation is tipically performed with which of the following machine tools? - Milling machine - Drill press - Planer - Shaper - Lathe 21. In the orthogonal cutting model, the chip thickness ratio is defined as (where tc=thickness of the chip, wc= width of the chip, tm= thickness of the material to be cut, wm= width of the material to be cut, f=feed) - wm/wc - wc/wm - tm/tc - tc/f - tc/tm 22. which are the forces that can be physically (directly) measured in a cutting process with a single-edged tool - cutting force and friction force - friction force and normal friction force - shear force and normal shear force - thrust force and shear force - cutting force and thrust force (Slide 36 cap.9 Theory Of MM) - none of the other answers 23. Assuming you measure the engineering and true stresses simultaneously during a tensile test, which of the following statements are correct - Engineering stress is always lower than true stress - Engineering stress is lower than true stress only after the sample necking - Engineering stress is always higher than true stress - None of the above - Engineering stress is lower than true stress only after the sample necking 24. Which of the following statements is correct about milling? - A vertical knee-and-coloumn is normally used to perform peripheral milling. - None of the answers. - In end milling, the cutter overhangs the work on only one side - In conventional milling (or up milling) the direction of cutter motion is the same as the feed direction when the teeth cut the work - A horizontal knee-and-coloumn milling machine is used to perform face milling - In climb milling (or down milling) the direction of cutter motion is opposite to the feed direction when the teeth cut the work 25. Which is/are the manufacturing process/processes that could be also used (with proper equipment and/or tools) to produce threaded part? - Turining - Planing - Broaching - Shaping - Rolling - Drawing 26. Which of the following statements is correct: - Merchant-Ernst theory is based on strain rate analysis - Pijspanen’s theory is based on the analysis of the shear motion of the chip on a plane parallel to the tool rake surface - None of the others - Merchant-Ernst theory, differently from the Pijspanen’s theory, introduces the phenomenon of friction - Pijspanen’s theory, differently from the Merchant-Ernst theory, introduces the phenomenon of friction 27. In chip removal machining operations: - There is a decrease in hardness in the chip, compared to the base material - There is no plastic deformation of the material - None of the others - There is an elastic deformation of the material highlighted by the chip thickness ratio - There is a plastic deformation of the material highlighted by the chip thickness ratio 28. The taylor’s law for cutting tool life is applicable: - Only for tool with flank wear of 0.5 mm - Only for a tool life of more than 60 minutes - In most cases of cutting processes - None of the others - Exclusively for sintered carbide and high-speed steel tools 29. The built-up edge: - Alters the relief (clearance) angle - None of the other answers - Alters the rake angle - Alters the cutting edge angle 30. For the determination of Taylor’s law - None of the others - The values of the constants n and C are obtained directly from the measurement of the flank wear - The experimental values obtained from the measurement of the crater wear as a function of time and cutting speed values are plotted (in a graph Vt-T) - The experimental values obtained from the measurement of the flank wear as a function of time and cutting speed are plotted (in a graph Vt-T) - The values obtained from the measurement of the nose radius as a function of time and cutting speed values are plotted (in a graph Vt-T) 31. The reduction of the strain rate tends to have one of the following effects on the plastic flow stress and on the behaviour of the metal during cold plastic deformation (Hollomon equation (σ=Kε ) ) n - Decreases the plastic flow stress - Increases the plastic flow stress - Reduces ductility - Modifies Young’s modulus - None of the others 32. The increase of the strain rate tends to have one of the following effects on the plastic flow stress and on the behaviour of the metal during cold plastic deformation (Hollomon n equation (σ=Kε ) ) - Decreases the plastic flow stress - Increases the plastic flow stress - Increases ductility - Modifies Young’s modulus - None of the others 33. Which of the following factor most affects the rake angle: - The flank wear - Wear on the nose radius of the tool - The crater wear - None of the other answers - The built-up edge 34. The increase in temperature tends to have one of the following effects on the plastic flow stress and on the behaviour of the metal during cold plastic deformation (Hollomon n equation (σ=Kε ) ) - Decreases the plastic flow stress - Increases the plastic flow stress - Reduces ductility - Significantly changes Young’s modulus - None of the others