MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30

Transcription

1 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-1 (Session: ) MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). Why there is no material wastage in forming process? (Q.No.2) [5] Q-2). A 24mmX24mmX150mm copper plate is forged between two flat dies to a final size of 6mmX96mmX150mm. Determine the peak forging force, assuming the coefficient of friction to be The tensile yield stress of copper is 7 N/mm 2. Assume no strain hardening. (Q.No.9) [5] Q1. Prove that the average pressure Pa=2K(1+b/4h), where K, b and h are shear yield stress, length and height respectively. Why we take frictional stress x=k in case of sliding friction. [6+2=8] Q2. In what ways Hot working is different from cold working? Give at least five parameters in support of your answer. [5] Q3. What is Von Mises yield criteria? Using Von Mises criteria, show that the shear yield stress of the material s=σy/ 3, where σy is tensile yield stress of the material. [3+4=7] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 06 / 02 / 2012

2 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-1 (Session: ) MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). How is casting process different from machining process? (Q.No.1) [5] Q-2). A metal component 25mm X 25mm X 150mm having a yield stress of 7 MPa in simple tension is to be pressed between flat dies to a size 6mm X 100mm X 150mm. If μ= 0.2, calculate the maximum forging load. (Q.No.10) [5] Q1. Prove that the average pressure Pa=2K(1+b/4h), where K, b and h are shear yield stress, length and height respectively. Why we take frictional stress x=k in case of sliding friction. [6+2=8] Q2. In what ways Hot working is different from cold working? Give at least five parameters in support of your answer. [5] Q3. What is Von Mises yield criteria? Using Von Mises criteria, show that the shear yield stress of the material s=σy/ 3, where σy is tensile yield stress of the material. [3+4=7] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 06 / 02 / 2012

3 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-1 (Session: ) MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). Explain, why the understanding of manufacturing processes is essential for better products? (Q.No.3) [5] Q-2). What is work formula? How this is accounted for metal working? (Q.No.5) [5] Q1. Prove that the average pressure Pa=2K(1+b/4h), where K, b and h are shear yield stress, length and height respectively. Why we take frictional stress x=k in case of sliding friction. [6+2=8] Q2. In what ways Hot working is different from cold working? Give at least five parameters in support of your answer. [5] Q3. What is Von Mises yield criteria? Using Von Mises criteria, show that the shear yield stress of the material s=σy/ 3, where σy is tensile yield stress of the material. [3+4=7] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 06 / 02 / 2012

4 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-1 (Session: ) MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). An aluminium alloy yields at a stress of 50 MPa in uniaxial tension. If this material is subjected to the stresses σ 1 = 25MPa, σ 2 = 15 MPa, and σ 3 = -26 MPa, will it yield? Explain. (Q.No.6) [5] Q-2). A circular disc of lead of radius 150 mm and thickness 50 mm is reduced to a thickness of 25 mm by open die forging. If the coefficient of friction between the job and die is 0.25, determine the maximum forging load. The average shear yield stress of lead is 4N/mm ². (Q.No.8) [5] Q1. Prove that the average pressure Pa=2K(1+b/4h), where K, b and h are shear yield stress, length and height respectively. Why we take frictional stress x=k in case of sliding friction. [6+2=8] Q2. In what ways Hot working is different from cold working? Give at least five parameters in support of your answer. [5] Q3. What is Von Mises yield criteria? Using Von Mises criteria, show that the shear yield stress of the material s=σy/ 3, where σy is tensile yield stress of the material. [3+4=7] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 06 / 02 / 2012

5 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-1 (Session: ) MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). Describe the factors affecting plastic deformation. (Q.No.4) [5] Q-2). What are the advantages of open die and closed die forging process? Explain open die forging process in brief. (Q.No.7) [5] Q1. Prove that the average pressure Pa=2K(1+b/4h), where K, b and h are shear yield stress, length and height respectively. Why we take frictional stress x=k in case of sliding friction. [6+2=8] Q2. In what ways Hot working is different from cold working? Give at least five parameters in support of your answer. [5] Q3. What is Von Mises yield criteria? Using Von Mises criteria, show that the shear yield stress of the material s=σy/ 3, where σy is tensile yield stress of the material. [3+4=7] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 06 / 02 / 2012

6 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-2 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Explain backward extrusion with neat sketch and also state its application. [Q.NO.1 (TUTE-2)] [5] Q2) An aluminium rod 5.25 mm in diameter is drawn into a wire of 5 mm in diameter. The half die angle is 8 º.Determine the drawing stress considering friction if coefficient of friction is 0.03 and shear yield stress for aluminium is 30 N/mm 2, when (i) back pull is zero, and (ii) back pull is 300 N. [Q.NO.4 (TUTE-2)] [4+1] Q1) Calculate the drawing load for 40% reduction of area of 30 mm X 6 mm annealed mild steel strip using straight tapered die. Take µ = 0.1, α = 26 º and σ y = 30 kgf/mm 2. [4+2] Q2) What is Tube drawing? State its types and explain any one of them with neat sketch. [1+3] Q3) Prove that condition for rolling is µ tanα and that is leads to R (h i-h f)/µ 2 where µ is coefficient of friction, α bite angle, R roll radius and h i and h f are initial and final strip thickness. Also considering the curved area under rolls as an analogue of rectangular block (bxh) being forged, show that the mean roll pressure P mean 2K 1 where L is the roll contact length with strip, average strip thickness is h ; using formula for pressure distribution for forging of a rectangular block with sliding friction (with µ small, exponential formula may be expanded as 1. [4+6] EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 03/03/2012

7 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-2 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Mention the advantages and limitations of extrusion process. [Q.NO.3 (TUTE-2)] [2+3] Q2) Find the draw stress of a wire of size 4 mm from a rod of 5 mm through conical die of semi die angle 15 º with µ = 0.05 and K = 200 N/mm 2. Assume no back tension. Also find how many draws are required to draw a wire of 1 mm from a rod of 5 mm, other data being same as before. [Q.NO.5 (TUTE-2)] [3+2] Q1) Calculate the drawing load for 40% reduction of area of 30 mm X 6 mm annealed mild steel strip using straight tapered die. Take µ = 0.1, α = 26 º and σ y = 30 kgf/mm 2. [4+2] Q2) What is Tube drawing? State its types and explain any one of them with neat sketch. [1+3] Q3) Prove that condition for rolling is µ tanα and that is leads to R (h i-h f)/µ 2 where µ is coefficient of friction, α bite angle, R roll radius and h i and h f are initial and final strip thickness. Also considering the curved area under rolls as an analogue of rectangular block (bxh) being forged, show that the mean roll pressure P mean 2K 1 where L is the roll contact length with strip, average strip thickness is h ; using formula for pressure distribution for forging of a rectangular block with sliding friction (with µ small, exponential formula may be expanded as 1. [4+6] EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 03/03/2012

8 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-2 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Describe (with the help of neat sketches) various types of rolls used during rolling process. [Q.NO.8 (TUTE-2)] [5] Q2) Estimate the roll force and power for annealed low carbon steel strip 400 mm wide and 10 mm thick, rolled to a thickness of 7 mm. The roll radius is 200 mm and the roll rotates at 200 rpm. Take µ = 0.1 [Q.NO.10 (TUTE-2)] [4+1] Q1) Calculate the drawing load for 40% reduction of area of 30 mm X 6 mm annealed mild steel strip using straight tapered die. Take µ = 0.1, α = 26 º and σ y = 30 kgf/mm 2. [4+2] Q2) What is Tube drawing? State its types and explain any one of them with neat sketch. [1+3] Q3) Prove that condition for rolling is µ tanα and that is leads to R (h i-h f)/µ 2 where µ is coefficient of friction, α bite angle, R roll radius and h i and h f are initial and final strip thickness. Also considering the curved area under rolls as an analogue of rectangular block (bxh) being forged, show that the mean roll pressure P mean 2K 1 where L is the roll contact length with strip, average strip thickness is h ; using formula for pressure distribution for forging of a rectangular block with sliding friction (with µ small, exponential formula may be expanded as 1. [4+6] EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 03/03/2012

9 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-2 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Explain in brief major effect of friction in forming operations and also the role of lubrication in forming operations. [Q.No.7 (TUTE-2)] [2+3] Q2) Calculate the bite angle when rolling plates 15 mm thick using work rolls 400 mm diameter, reduces the thickness by 3 mm. [Q.No.9 (TUTE-2)] [5] Q1) Calculate the drawing load for 40% reduction of area of 30 mm X 6 mm annealed mild steel strip using straight tapered die. Take µ = 0.1, α = 26 º and σ y = 30 kgf/mm 2. [4+2] Q2) What is Tube drawing? State its types and explain any one of them with neat sketch. [1+3] Q3) Prove that condition for rolling is µ tanα and that is leads to R (h i-h f)/µ 2 where µ is coefficient of friction, α bite angle, R roll radius and h i and h f are initial and final strip thickness. Also considering the curved area under rolls as an analogue of rectangular block (bxh) being forged, show that the mean roll pressure P mean 2K 1 where L is the roll contact length with strip, average strip thickness is h ; using formula for pressure distribution for forging of a rectangular block with sliding friction (with µ small, exponential formula may be expanded as 1. [4+6] EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 03/03/2012

10 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-2 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) What is the difference between drawing and extrusion? What types of defects may occur in drawing and Extrusion? [Q.No.2 (TUTE-2)] [2+3] Q2) A strip with a cross section 150 mm x 4.5 mm is being rolled with 20 % reduction of area using 450 mm diameter rolls, find (i) the angle subtended by the deformation zone at the roll centre, (ii) the final strip thickness. Take µ = 0.1 [Supp.Q.No.2 (TUTE-2)] [3+2] Q1) Calculate the drawing load for 40% reduction of area of 30 mm X 6 mm annealed mild steel strip using straight tapered die. Take µ = 0.1, α = 26 º and σ y = 30 kgf/mm 2. [4+2] Q2) What is Tube drawing? State its types and explain any one of them with neat sketch. [1+3] Q3) Prove that condition for rolling is µ tanα and that is leads to R (h i-h f)/µ 2 where µ is coefficient of friction, α bite angle, R roll radius and h i and h f are initial and final strip thickness. Also considering the curved area under rolls as an analogue of rectangular block (bxh) being forged, show that the mean roll pressure P mean 2K 1 where L is the roll contact length with strip, average strip thickness is h ; using formula for pressure distribution for forging of a rectangular block with sliding friction (with µ small, exponential formula may be expanded as 1. [4+6] EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 03/03/2012

11 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-3 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) How does the grain size distribution of moulding sand affect strength and permeability? [Q.NO.3 (TUTE-3)] [5] Q2) Explain the design consideration of open riser. [Q.NO.7 (TUTE-3)] [5] Q1) Give causes and remedies of the following casting defects: [ ] (i) Blow holes (ii) Pin hole (iii) Rat tails (iv) Hot tear Q2) Describe all the desirable properties of a moulding sand. [5] Q3) A mould 60cm x 30cm x 14cm is to be filled by liquid metal during sand casting process. Determine the time taken to fill up the mould using: [3+4] (i) Top gating system (ii) Bottom gating system The cross-sectional area of gate is 6 cm 2 EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 24/03/2012

12 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-3 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Define aspiration effect in castings. Draw the schematic view of ideal and actual shapes of sprue. Derive the governing equation to avoid aspiration. [Q.NO.6 (TUTE-3)] [2+3] Q2) When do you use (a) top gating system (b) bottom gating system. [Q.NO.10 (TUTE-3)] [ ] Q1) Give causes and remedies of the following casting defects: [ ] (i) Blow holes (ii) Pin hole (iii) Rat tails (iv) Hot tear Q2) Describe all the desirable properties of a moulding sand. [5] Q3) A mould 60cm x 30cm x 14cm is to be filled by liquid metal during sand casting process. Determine the time taken to fill up the mould using: [3+4] (i) Top gating system (ii) Bottom gating system The cross-sectional area of gate is 6 cm 2. EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 24/03/2012

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14 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-3 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Describe die casting process with neat sketch. [Q.NO.2 (TUTE-3)] [5] Q2) What is directional solidification? How is it achieved? [Q.NO.5 (TUTE-3)] [3+2] Q1) Give causes and remedies of the following casting defects: [ ] (i) Blow holes (ii) Pin hole (iii) Rat tails (iv) Hot tear Q2) Describe all the desirable properties of a moulding sand. [5] Q3) A mould 60cm x 30cm x 14cm is to be filled by liquid metal during sand casting process. Determine the time taken to fill up the mould using: [3+4] (i) Top gating system (ii) Bottom gating system The cross-sectional area of gate is 6 cm 2 EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 24/03/2012

15 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-3 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Describe the capabilities of the casting process in terms of shape and size of the product. [Q.No.4 (TUTE-3)] [5] Q2) Describe investment casting process with neat sketch. [Q.No.9 (TUTE-3)] [5] Q1) Give causes and remedies of the following casting defects: [ ] (i) Blow holes (ii) Pin hole (iii) Rat tails (iv) Hot tear Q2) Describe all the desirable properties of a moulding sand. [5] Q3) A mould 60cm x 30cm x 14cm is to be filled by liquid metal during sand casting process. Determine the time taken to fill up the mould using: [3+4] (i) Top gating system (ii) Bottom gating system The cross-sectional area of gate is 6 cm 2 EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 24/03/2012

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17 B.Tech. [SEM IV (ME-41, 42, 43, 44)] QUIZ TEST-3 Time: 1 Hour MANUFACTURING SCIENCE-I Max. Marks: 30 (EME-402) Note: Attempt all the questions. Q1) Define choke area in castings. Explain reasons as to why sprue base is normally used as the choke area for ferrous castings? [Q.No.1 (TUTE-3)] [2+3] Q2) Sketch and briefly describe cupola furnace. [Q.No.8 (TUTE-3)] [5] Q1) Give causes and remedies of the following casting defects: [ ] (i) Blow holes (ii) Pin hole (iii) Rat tails (iv) Hot tear Q2) Describe all the desirable properties of a moulding sand. [5] Q3) A mould 60cm x 30cm x 14cm is to be filled by liquid metal during sand casting process. Determine the time taken to fill up the mould using: [3+4] (i) Top gating system (ii) Bottom gating system The cross-sectional area of gate is 6 cm 2 EME-402/Mr. Mayank Kumar & Mr. Vinay Kushwaha Date: 24/03/2012

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19 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-4 (Session: ) MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). Calculate the bending force for a 45 0 bend of aluminum sheet 1.6 mm thick and 1200 mm long with a die opening 8 times the metal thickness. The bend is to be made by air bending method. The ultimate tensile strength is 300 MPa. (Q.No.10) [5] Q-2). Why does a metal becomes thinner in the region of a bend? (Q.No.5) [5] Q1. Differentiate the compound die from progressive die on the basis of constructional features and working method. [5] Q2. What is the significance of Clearance in the die and punch assembly? What are the rules for providing, Clearance in Blanking and piercing operations? [2+5] Q3. What is the difference between Nibbling and Lancing? Explain the process of Deep drawing with neat sketch. [4+4=8] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 14 / 04 / 2012

20 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-4 (Session: ) MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). A 400 mm long, 20 mm wide and 2.5 mm thick strip is to be bent in a V-bending die. Calculate the bending force necessary, if the steel has tensile strength of 630 N/mm 2. (Q.No.8) [5] Q-2). What is the function of the pressure ring or hold down in a deep drawing operation? (Q.No.3) [5] Q1. Differentiate the compound die from progressive die on the basis of constructional features and working method. [5] Q2. What is the significance of Clearance in the die and punch assembly? What are the rules for providing, Clearance in Blanking and piercing operations? [2+5] Q3. What is the difference between Nibbling and Lancing? Explain the process of Deep drawing with neat sketch. [4+4=8] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 14 / 04 / 2012

21 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-4 MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). Calculate the bending force required for a steel sheet 1.6 mm thick and 1.2 mm wide is to be bent in a wiping die. The die radius is 3 mm and the ultimate tensile strength is 800 MPa. (Q.No.9) [5] Q-2). Describe, why earing occurs and how could you avoid it? (Q.No.4) [5] Q1. Differentiate the compound die from progressive die on the basis of constructional features and working method. [5] Q2. What is the significance of Clearance in the die and punch assembly? What are the rules for providing, Clearance in Blanking and piercing operations? [2+5] Q3. What is the difference between Nibbling and Lancing? Explain the process of Deep drawing with neat sketch. [4+4=8] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 14 / 04 / 2012

22 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-4 MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). Why are sheared and blanked edges generally not smooth? (Q.No.2) [5] Q-2). Determine blank diameter to make a tapered shell as shown in figure below: (dimensions are in mm.) (Q.No.7) [5] Q1. Differentiate the compound die from progressive die on the basis of constructional features and working method. [5] Q2. What is the significance of Clearance in the die and punch assembly? What are the rules for providing, Clearance in Blanking and piercing operations? [2+5] Q3. What is the difference between Nibbling and Lancing? Explain the process of Deep drawing with neat sketch. [4+4=8] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 14 / 04 / 2012

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24 B.Tech. [SEM-IV (ME-41,42,43 & 44] QUIZ TEST-4 MANUFACTURING SCIENCE-I Time: 1 hour (EME-402) Max. marks:30 Note: All questions are compulsory. Q-1). On what factors the selection of press for sheet metal forming operation depend? (Q.No.1) [5] Q-2). Calculate the blank diameter to make a steel shell as shown in figure below: (dimensions are in mm.) (Q.No.6) [5] Q1. Differentiate the compound die from progressive die on the basis of constructional features and working method. [5] Q2. What is the significance of Clearance in the die and punch assembly? What are the rules for providing, Clearance in Blanking and piercing operations? [2+5] Q3. What is the difference between Nibbling and Lancing? Explain the process of Deep drawing with neat sketch. [4+4=8] EME-402 / Mr. V. K. Kushwaha/Mayank Kumar Date: 14 / 04 / 2012

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