Definition of chip: Types,Factor and Condition of chip

Introduction

·        Metal cutting is the process of producing work-piece by removing unwanted material from a block of metal, in the form of chips.

·        This process is most important because almost all products get their final shape and size directly or indirectly by machining.

·        Its major draw back is that in this process there is a lot of material lost in the form of chips.

Machine Of Chips Formation

§  When the tool makes contact with the work-piece it exerts pressure on it resulting in compression of the metal near the tool tip.

§  This induces shear-type deformation within the metal it start moving upward along the face of the tool.

§  As the tool advances this process of shearing goes on increasing and material removed.

Chips Formation Process

•      Shaping
•           Turning
•            Milling
•           Drilling
•           Sawing
•           Broaching
•           Grinding

Basic Cutting-Face Cutting

Basic Cutting-Pocket Cutting

Basic Cutting-Turning Diameters

Basic Cutting-Thread Cutting

Basic Cutting-Surface Grinding

Chip Formation Process

Control

•   Feed
•  Speed
•   Depth of cut

Condition

•  Machine process
• Machine limitation
• Material
• Tool type
• Tool material
• Surface finish
• Tolerance

Factors Of Chip Formation

§  Nature of the work piece
§  Nature of tool
§  Dimension of tool
§  Feed rate
§  Cutting speed
§  Friction between tool and work-piece
§  Cutting environment ( temp, friction etc)

Types

There are three types of chip

1. Discontinuous
2.  Continuous
3.  Continuous with built-up-edge

Continuous

     If the metal chips are formed during machining is without segment i.e without breakage.

Discontinuous

•        If the chips is formed during machining is not continues i.e formed with breakage.
•        Its formed when material is hard and brittle metals i.e brass and cast iron.

Build up edge

•        Continuous chips with build up edge is formed by machining ductile material with high friction at the chip tool inter-face.