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is mainly about surface roughness. Another class of surface integrity is called surface metallurgy which provides information about the nature of surface layer produced in
machining.
Believing the information relating about machining hard material such as AISI D2 using plasma assisted machining is inadequate, this project was conducted to
investigate about the surface integrity of AISI D2 steel when machining using plasma assisted machining. The methodology used in this project is experimental
procedures. A device called Scanning Electron Microscope SEM is employed to accomplish research objective.
This experimental will be performed by using Plasma Assisted Machining. The parameters that will involve in this plasma cutting process are current, feed rate, air
pressure and arc gap. Plasma arc cutter used to cut AISI D2 Tool Steel 100 mm x 100 mm x 20 mm based on the selected parameters setting.
1.2 Problem Statement
AISI D2 Tool Steel is the most common material used in cutting tool industry because it exhibit great mechanical properties such as high wear resistance, high
strength and toughness. Plasma Cutting is the most ideal machining that is suitable to machined AISI D2. Plasma cutter is a type of machining that utilizes heat as a
medium for cutting. In this process, plasma torch use high velocity of ionized gas called plasma to remove metal by melting. Typically, the operating temperature of
Plasma is in the range of 20,000° to 50,000° F 11,000° to 28,000° C. Despite the great qualities produced by plasma cutting, however the most common issue arises is
that the high temperature of plasma will modify the surface integrity of the material. The material changes occur at the subsurface zones or internal features. The
properties at the sub-surface zone are distinctive from the properties at the bulk material. This structure changes is referred to as altered material zones AMZ or
layers. It is also known as Heat Affected Zone HAZ. The changes of surface integrity will affect to the performance of materials.
Besides, this study is conducted due to the limited study about the surface alteration encountered by AISI D2 using
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plasma cutting. Besides, this study is conducted due to the limited study about the surface alteration encountered by AISI D2 using plasma cutting.
1.3 Objectives
The objectives of this experiment are: a To characterize the surface integrity of the AISI D2 when machining
using plasma assisted machining. b To investigate the effect of the cutting parameters selected of air plasma
=cutting on the surface integrity.
1.4 Scope of Project
The scope of this project is to perform machining operation for AISI D2 Tool Steel by using Air Plasma Cutting. The parameter varying is air pressure, current, feed rate
arc gap. The performance measure to be evaluated is surface integrity.. Analysis about the surface integrity of AISI D2 after machining by using plasma arc cutting is
made with the aid of special devices called Scanning Electron Microscope SEM. Aspect to be covered when evaluating the surface integrity is surface metallurgy
which involves microstructure alteration, phase transformation, heat affected zone and microhardness of AISI D2.
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This chapter covers about general knowledge of this thesis. The aim of literature review is to establish a theoretical framework with substantive findings and
methodological contribution to this project which includes all the knowledge such as process, work piece will be explained.
2.1 Classification of Machining Process
