17.11 Name and briefly describe the four types of chips that occur in metal cutting.
Answer. The four types are (1) discontinuous, in which the chip is formed into separated segments; (2) continuous, in which the chip does not segment and is formed from a ductile metal; (3) continuous with built up edge, which is the same as (2) except that friction at the tool chip interface causes adhesion of a small portion of work material to the tool rake face, and (4) serrated, which are semi-continuous in the sense that they possess a saw-tooth appearance that is produced by a cyclical chip formation of alternating high shear strain followed by low shear strain.
17.12 Identify the four forces that act upon the chip in the orthogonal metal cutting model but cannot be measured directly in an operation.
Answer. The four forces that act upon the chip are (1) friction force, (2) normal force to friction, (3) shear force, and (4) normal force to friction.
17.13 Identify the two forces that can be measured in the orthogonal metal cutting model.
Answer. The two forces that can be measured in the orthogonal metal cutting model are (1) cutting force and (2) thrust force.
17.14 What is the relationship between the coefficient of friction and the friction angle in the orthogonal cutting model?
Answer. The relationship is that the coefficient of friction is the tangent of the friction angle ( = tan ).
17.15 Describe in words what the Merchant equation tells us.
Answer. The Merchant equation states that the shear plane angle increases when rake angle is increased and friction angle is decreased.
17.16 How is the power required in a cutting operation related to the cutting force?
Answer. The power required in a cutting operation is equal to the cutting force multiplied by the cutting speed.
17.17 What is the specific energy in metal machining?
Answer. Specific energy is the amount of energy required to remove a unit volume of the work material.
17.18 What does the term size effect mean in metal cutting?
Answer. The size effect refers to the fact that the specific energy increases as the cross sectional area of the chip (to x w in orthogonal cutting or f x d in turning) decreases.
17.19 What is a tool chip thermocouple?
Answer. A tool chip thermocouple is comprised of the tool and chip as the two dissimilar metals forming the thermocouple junction; as the tool chip interface heats up during cutting, a small voltage is emitted from the junction that can be measured to indicate cutting temperature.
17.11 Name and briefly describe the four types of chips that occur in metal cutting. Answer. The four types are (1) discontinuous, in which the chip is formed into separated segments; (2) continuous, in which the chip does not segment and is formed from a ductile metal; (3) continuous with built up edge, which is the same as (2) except that friction at the tool chip interface causes adhesion of a small portion of work material to the tool rake face, and (4) serrated, which are semi-continuous in the sense that they possess a saw-tooth appearance that is produced by a cyclical chip formation of alternating high shear strain followed by low shear strain.17.12 Identify the four forces that act upon the chip in the orthogonal metal cutting model but cannot be measured directly in an operation. Answer. The four forces that act upon the chip are (1) friction force, (2) normal force to friction, (3) shear force, and (4) normal force to friction. 17.13 Identify the two forces that can be measured in the orthogonal metal cutting model. Answer. The two forces that can be measured in the orthogonal metal cutting model are (1) cutting force and (2) thrust force. 17.14 What is the relationship between the coefficient of friction and the friction angle in the orthogonal cutting model? Answer. The relationship is that the coefficient of friction is the tangent of the friction angle ( = tan ). 17.15 Describe in words what the Merchant equation tells us. Answer. The Merchant equation states that the shear plane angle increases when rake angle is increased and friction angle is decreased. 17.16 How is the power required in a cutting operation related to the cutting force? Answer. The power required in a cutting operation is equal to the cutting force multiplied by the cutting speed.17.17 What is the specific energy in metal machining? Answer. Specific energy is the amount of energy required to remove a unit volume of the work material.17.18 What does the term size effect mean in metal cutting? Answer. The size effect refers to the fact that the specific energy increases as the cross sectional area of the chip (to x w in orthogonal cutting or f x d in turning) decreases.17.19 What is a tool chip thermocouple?Answer. A tool chip thermocouple is comprised of the tool and chip as the two dissimilar metals forming the thermocouple junction; as the tool chip interface heats up during cutting, a small voltage is emitted from the junction that can be measured to indicate cutting temperature.
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