Discontinuous chips and continuous chips

                                    Discontinuous chips

• Discontinuous chips are formed during machining of brittle material.
• The factor responsible for the formation of discontinuous chips are low cutting speed and small rake angle.
• Cast iron during machining produces discontinuous chips.

• Continuous chips 
• Continuous chips are formed during machining of ductile material.
•   The factor responsible for the formation of continuous chips are high cutting speed and large rake angle
• In continuous chips cutting, the maximum heat depends upon the velocity of cutting.
• The continuous chips are in the form of long coils having the same thickness  steel durithroughout. 
• Mild steel during produces continuous chips.
•     In continuous chips with built up edge :-

1. In continuous chips with built up edge are formed during machining of ductile material.

 2. The factors responsible for the formation of continuous chips with built up edge is low cutting speed and small rake angle.
 3. cutting edge of the tool is dull,then during machining continuous chips with built up edge are formed..
4.  If the cutting speed is increased, then  the built up edge becomes smaller and finally doesn't form a  2. The factors responsible for the 

Oblique cutting system (production process or manufacturing process)

• In Oblique cutting of metals , the cutting edge of the tool is inclined at an as angle less than 90° to the direction of the tool travel.
• In Oblique cutting system , the cutting edge of the tool may not clear the width of the workpiece (W/P).
• Frequently, more than one cutting edge are in motion.
• The chips flows on the tool face at an angle less than 90° with the normal on the cutting edge.
• In Oblique cutting system , the tool may or may not generate a surface parallel to the workpiece.
• In Oblique cutting system ,the maximum chip thickness doesn't occurs at the middle.
• In Oblique cutting system, is 3D in nature Fc,Ff,Fr.
• In Oblique cutting system force acts on large area hence changes of tool failure is low.
• In Oblique cutting system, the tool life is high.

orthogonal cutting of metal(production process)

(1) In orthogonal cutting of metal the cutting edge of the tool is perpendicular to the direction of the tool travel . i.e Q= 90° .

(2) In orthogonal cutting of metal the cutting forces occurs in two direction only.

(3)  In orthogonal cutting of metal the cutting tool life is low .

(4) In orthogonal cutting of metal the cutting surface roughness is poor .

(5)  In orthogonal cutting of metal the cutting the chips flows over the tool face and the direction of the chip flow velocity is normal to the cutting edge.

(6)  In orthogonal cutting system, the maximum chip thickness occurs at the middle.

(7) In orthogonal cutting of metal chips curls in spiral fashion.

(8)  In orthogonal cutting of metal the cutting it is 2D in nature . i.e. Fc,Ft .

(8)In orthogonal cutting, the depth of cut is half and the feed rate is double,if the chips thickness ratio is unaffected with the changed cutting conditions, the actual thickness will be double.