The
famous machines to produce shape are Lathe Machine and Milling Machine. But
various shapes can be produced by other machine namely Broaching, Sawing, Filing, and Gear Manufacturing. Some machine such as grinding machine is designed to
produce various shape which focuses on precision and superb surface finish.
Turning
machine is used to produce round shape and hole making. While milling machine
used to produce various shape. These two machines are famous and the capability of the machine time to time
always upgraded.
Nowadays
the complex shape with quality surface finish can be machining and achieved
easily. The machine maker always tries to ease the operator for marketing and selling
strategy. The strategy of making performance milling and lathe machine always
in the mind of manufacturer. Normally they go online with the capability of
Computer Aided Design (CAD) and Computer Aided Machining (CAM).
No
doubt in near future female can operate the process of producing product start from
design, machining, and prototyping. This support by operating
machine in conducive environment.
Job
transform from men to women happen everywhere. Nowadays, we can see that women
can operate the machine very well. The advantage of the
women operator because they have the right attitude and patience. Therefore, it is good news
for a female engineer who are very potential to develop their engineering
career, especially in machining technology.
Not
to forget billions of moneys are generated by milling and turning machine.
To maximize the potential of the material remover process, it cannot compromise
on the operator side who must know the cutting material, cutting tool technology,
type of cutting fluid and machining trend in near future. To be specified 5 things to
consider in material remover are:
1.
Types and characteristics of cutting-tool materials. The selection of cutting-tool materials for a particular
application is among the most crucial factors in machining operations, as is the selection of
mold and die materials for forming and shaping processes. The critical of tool
material selection because it happen that in many conditions the
materials are same used in mold and die. The cutting tool criteria to consider
is subjected to (a) high temperatures, (b) high contact stresses, and (c) rubbing along
the tool–chip interface and along the machined surface. Thus, for example:
First, hardness and strength are important regarding the hardness and
strength of the workpiece material to be machined. Second, the impact
strength is important in making interrupted cuts in machining, such as milling.
Third, melting temperature of the tool material is important versus the
temperatures developed in the cutting zone. Fourth, the physical properties of
thermal conductivity and coefficient of thermal expansion are important in determining the
resistance of the tool materials to thermal fatigue and shock.
2.
Properties and applications of high-speed steels, carbides, ceramics, cubic
boron nitride, and diamond. The application of tool properties is based
on what material you want to cut and the quality of cutting. Do not forget
also on surface finish, machining time and cost effectiveness. To cut cost but maintaining the
quality of product normally we used insert and tool holder.
3.
Coatings on tools, their composition, and how they function. These are important in machining process, to cut
costs in cutting material. Insert widely used by coated technology for maintaining cutting
tool properties. The normally coated tool has unique properties such as (a) lower friction,
(b) higher adhesion, (c) higher resistance to wear and impact, and (d)
acting as diffusion barrier.
4.
Types of cutting fluids and their applications.
Cutting fluids have been used extensively in machining operations to achieve the
results or (a) Reduce friction and wear, thus improving tool life and the
surface finish of the workpiece. (b) Cool the cutting zone, thus improving tool
life and reducing the temperature and thermal distortion of the workpiece. (c)
Reduce forces and energy consumption. (d) Flush away the chips from the cutting
zone, and thus prevent the chips from interfering with the cutting process,
particularly in operations such as drilling and tapping. (e) Protect the
machined surface from environmental corrosion.
Depending
on the type of machining operation, the cutting fluid needed may be a coolant,
a lubricant, or both. The effectiveness of cutting fluids depends on several factors,
such as the type of machining operation, tool, and workpiece materials, cutting speed, and the
method of application.
Water
is an excellent coolant and can reduce effectively the high
temperatures developed in the cutting zone.
Types
of cutting fluids, briefly, four general types of cutting fluids commonly are
used in machining operations such as.
Oils (also called straight oils) including mineral,
animal, vegetable, compounded, and synthetic oils typically are used for
low-speed operations where temperature rise is not significant. Emulsions (also
called soluble oils) are a mixture of oil and water and additives, are used
for high-speed operations because temperature rise is significant. The presence
of water makes emulsions highly effective coolants. Semisynthetic are
chemical emulsions containing little mineral oil, diluted in water, and with
additives that reduce the size of oil particles, making them more effective. Synthetics are
chemicals with additives, diluted in water, and contain no oil.
5.
Trends in near-dry and dry machining.
This
trend has lead to the practice of near-dry machining (NDM) with major benefits
such as the environmental impact of using cutting fluids on making process up
to disposal. NDM improving air quality in manufacturing plants and reducing
health hazards. The most important to reduce the cost of machining operations,
including the cost of maintenance, recycling, and disposal of cutting fluids.
Further improving surface quality offer by dry machining. With major advances
in cutting tools, dry machining has been shown to be effective in various machining
operations (especially turning, milling, and gear cutting) on steels, steel
alloys, and cast irons, but not for aluminum alloys.
Cryogenic
machining also part of NDM which more recent developments in machining include
the use of cryogenic gases such as nitrogen or carbon dioxide as a coolant in
machining. With small-diameter nozzles and at a temperature of –200ºC, liquid
nitrogen is injected into the cutting zone. Because of the reduction in
temperature, tool hardness is maintained, and tool life is enhanced, thus allowing higher
cutting speeds.
Cryogenic
machining also produced more brittle chips, hence machinability is increased. Furthermore,
the nitrogen simply evaporates and thus has no adverse environmental impact.
