- Increasing cutting speed.
- Decreasing feed rate.
- Increasing ambient workpiece temperature.
- Increasing rake angle.
- Reducing friction (by applying cutting fluid)
What causes built-up edge?
When the friction between tool and chip is high while machining ductile materials
, some particles of chip adhere to the tool rake face near the tool tip. When such sizeable material piles up on the rake face, it acts as a cutting edge in place of the actual cutting edge. This is termed as built up edge (BUE).
What precautions are to be required to avoid built-up edge formation?
- When using carbide inserts, increase the cutting speed – if machining at high speed, the time available for adhering microchips will be less, and the formation of a built-up edge will be minimized.
- When using HSS cutting tools the opposite of the above can be true.
What is the built-up edge and why it is undesirable and how it can be reduced?
The tendency for built-up edge formation can be decreased by using
a tool that has a lower chemical affinity towards the workpiece material
. Built-up edge is undesirable because[Why a built up edge on a tool is undesirable?] Fluctuation in cutting force induces vibration that causes tool failure.
What is a built-up edge in machining?
The term built-up edge means that
the material that you’re machining is being pressure welded to the cutting tool
. When inspecting your tool, evidence of a BUE problem is material on the rake face or flank face of the cutting tool.
What are the factors responsible for built up edge in cutting tool?
Several important factors affect the built-up material formation, e.g.
cutting temperature, cutting speed, strain hardening
, adhesion between the work material and the tool, micro-crack formation, plastic flow of the work material in the vicinity of the cutting edge, etc.
When built-up edge is formed?
Built up edge is formed as
a result of the occurrence of the leading surface shear stress
, which under certain conditions at high pressure adhere the workpiece to the edge. This material is harder than 80% and takes over the role of the cutting edge.
What are the 3 types of chips?
Basically there are three types of chips produced in the metal machining and these are
continuous, discontinuous and continuous with built-up edge
.
What is tool life?
Tool life T is
the period of time, expressed in minutes
, for which the cutting edge, affected by the cutting procedure, retains its cutting capacity between sharpening operations. … In drilling and milling, one frequently makes use of the term tool life travel path rather than tool life.
What is continuous chip with built up edge?
Continuous Chips With the Built-Up Edge (BUE) The formation of continuous chips with the BUE is
caused by high friction between the tool and the chip while machining ductile metals
. Under these conditions, some chip particles tend to bond to the tooltip.
What is rake angle in cutting tool?
Rake angle is
a cutting edge angle that has large effects on cutting resistance, chip disposal, cutting temperature and tool life
. Increasing rake angle in the positive (+) direction improves sharpness. Increasing rake angle by 1° in the positive (+) direction decreases cutting power by about 1%.
What is chip morphology?
The chip morphology is
the result of specific chip formation mechanism(s) occurring during machining
. For monolithic metallic materials, the chip formation mechanism has been reported to be primarily due to (1) adiabatic shear localization [11–13] or (2) crack initiation and propagation [14,15].
What is continuous chip?
Continuous chip obtained
when cutting of ductile material like aluminium and low carbon steel
. The chips come out without fracture in the form of either long string or bend into a tight roll. If this chip hit finished parts of the work, it spoils the finished surface.
What is orthogonal cutting?
The term “orthogonal cutting” has been coined1 to
cover the case where the cutting tool generates a plane surface parallel to an original plane surface of the material being cut
and is set with its cutting edge perpendicular to the direction of relative motion of tool apd workpiece.
Which cutting condition affects the cutting temperature predominantly?
Cutting speed
affects cutting temperature predominantly – Manufacturing Processes – 2.
