What is surface roughness? Surface finish is one of the most important measures for determining the quality of products in machining. Explain in some details.

(a) Explain the difference between roughing and finishing operations in machining.(b) What are the parameters of a machining operation that are included within the scope of cuttingconditions?(c) What is the difference between threading and tapping?(d) A cylindrical workpiece is to be turned in a lathe. Determine the material removal rate if thecutting speed = 2.30 m/s, feed = 0.32 mm/rev, and depth of cut = 1.8 mm.(e) In a turning operation using high-speed steel tooling, the cutting speed = 110 m/min. The Taylortool life equation has parameters n = 0.140 and C = 150 (m/min) when the operation is conducteddry. When a coolant is used in the operation, the value of C is increased by 15%. Determine thepercent increase in tool life that will result if the cutting speed is maintained at 110 m/min.

For the following application, identify one or more nontraditional machining processes that might be used, and present arguments to support your selection. Assume that either the part geometry or the work material (or both) preclude the use of conventional machining. The application is a through-hole in the shape of the letter L in a 12.5 mm (0.5 in) thick plate of glass. The size of the "L" is 25 by 15 mm (1.0 by 0.6 in) and the width of the hole is 3 mm (1/8 in).

Problem 2. (Determining Cutting Speeds in Machining Economics) A turning operation is performed with HSS tooling on mild steel, with Taylor tool life parameters n = 0.12, C = 60 m/min. Work part length = 450 mm and diameter = 80 mm. Feed = 0.20 mm/rev. Handling time per piece = 4.0 min, and tool change time = 1.5 min. Cost of machine and operator = $27/hr, and tooling cost = $2 per cutting edge. Find the a. cutting speed for maximum production rate = 44.997m/min. b. cutting speed for minimum cost = 38.143m/min. Problem 3. (Production Rate and Cost in Machining Economics) For the two cutting speeds computed in problem 2, determine: a. the hourly production rate and b. the cost per piece. Need help with problem 3 already done problem 2

Problem 2. (Determining Cutting Speeds in Machining Economics) A turning operation is performed with HSS tooling on mild steel, with Taylor tool life parameters n = 0.12, C = 60 m/min. Work part length = 450 mm and diameter = 80 mm. Feed = 0.20 mm/rev. Handling time per piece = 4.0 min, and tool change time = 1.5 min. Cost of machine and operator = $27/hr, and tooling cost = $2 per cutting edge. Find the a. cutting speed for maximum production rate and b. cutting speed for minimum cost Problem 3. (Production Rate and Cost in Machining Economics) For the two cutting speeds computed in problem 2, determine: the hourly production rate and a. b. the cost per piece.

In plane-strain orthogonal machining, the two main sources of energy dissipation are deformation along the shear plane (~70%) and friction at the tool-chip contact along the rake face (~30%). Consider plane-strain machining of a rigid perfectly-plastic work material whose uniaxial yield stress is 700 MPa, and is independent of strain rate and temperature. A tool of zero-degree rake angle is employed. Measurements showed the (deformed) chip thickness to be twice that of the undeformed chip thickness. Based on the aforementioned distribution of energy, estimate the specific energy for this process.

In a production turning operation, the workpart is 60 mm in diameter and 500 mm long. A feed of 0.75 mm/rev is used in the operation. If cutting speed-9 m/s, the tool must be changed every 4 workparts; But if cutting speed=5 m/s, the tool can be used to produce 50 pieces between tool changes. Determine the Taylor tool life equation for this job. (use the equations given below for solution) L Tm- 1,= Nf N AD, vT" = C %3| AD,L Tm fv

In a production turning operation, the workpart is 60 mm in diameter and 500 mm long. A feed of 0.75 mm/rev is used in the operation. If cutting speed=9 m/s, the tool must be changed every 4 workparts; But if cutting speed=5 m/s, the tool can be used to produce 50 pieces between tool changes. Determine the Taylor tool life equation for this job. (use the equations given below for solution)

For the following application, identify one or more nontraditional machining processes that might be used, and present arguments to support your selection. Assume that either the part geometry or the work material (or both) preclude the use of conventional machining. The application is a blind-hole in the shape of the letter G in a 50 mm (2.0 in) cube of steel. The overall size of the "G" is 25 by 19 mm (1.0 by 0.75 in), the depth of the hole is 3.8 mm (0.15 in), and its width is 3 mm (1/8 in).

a) Define specific energy for plane strain machining (cutting).  b) In plane-strain orthogonal machining, the two main sources of energy dissipation are deformation along the shear plane (~70%) and friction at the tool-chip contact along the rake face (~30%). Consider plane-strain machining of a rigid perfectly-plastic work material whose uniaxial yield stress is 700 MPa, and is independent of strain rate and temperature. A tool of zero-degree rake angle is employed. Measurements showed the (deformed) chip thickness to be twice that of the undeformed chip thickness. Based on the aforementioned distribution of energy, estimate the specific energy for this process.