Machine and tool selection , Mechanical Engineering

Machine and Tool Selection

The quality of a product largely depends on the type of machine, the type of process, machining conditions and the right selection of tools. The current trend in manufacturing is to adopt more and more of automation of the fixed and flexible type. Hence, with a machine tool of a given level of automation the scope for improving productivity lies more and more in the selection and application of cutting tools.

Some of the factors influencing the selection of cutting tool are properties of tool materials, properties of work materials, the type of process, the accuracy and surface finish required, the cutting conditions, tool wear and tool life. The properties of tool material include Hardness, strength, Stiffness and Resilience, Wear resistance, Low coefficient of friction, Thermal Conductivity and Specific Heat. Some important tool materials used are High Carbon Steels, High Speed Steels, Cast Cobalt (Stellite) Tools, Carbides, Coated Carbides, Ceramics, Diamonds, Cubic Boron Nitride(CBN), Polycrystalline Diamond.

The important properties influencing the selection of cutting tools are : Hardness, Tensile strength, Modulus of elasticity, Chemical composition, Micro structure, Strain hardenability and thermal conductivity. The type of the manufacturing process depends upon the type of the tools used. Basically the tools can be classified into two types generating tools and forming tools. At the time of process planning the tools are selected depending on the accuracy and surface finish required. This is because of the fact that different operations and different tools would produce different accuracy levels and surfaces.

The tool life equation as proposed by Taylor is VTn = C

where  n = Constant for tool material,

V = Cutting speed, m/min, and

T = Tool life in min.

As this formula doesn't take into account all the effecting parameters, many researchers have extended this formula.

TQB = C

Equation 2

1229_Machine and Tool Selection.png

where  H = Specific heat × thermal conductivity,

θ = Tool temperature,

A = Area of cut,

us = Specific cutting energy/unit cutting force, and

C and x are constants.

VTnn1, dn2 = C         . . . (3)

where  f = Feed, mm/rev.,

d = Depth of cut, and

C = Constant.

All the cutting tools used in lathe are single point tools. The single point cutting tool nomenclature comprises the various parts of tool and systematic arrangement of tools angles. The tool angle are normally specified in the sequence of Back rake, Side rake, End relief, Side relief, End cutting edge, Side cutting edge angles and Nose radius. The various operations performed on a lathe machine are centering, turning, facing, thread cutting, knurling, parting off, forming, drilling, boring, and reaming. Similarly this unit discusses about the other type of tools used in milling and drilling.

Posted Date: 12/24/2012 5:06:10 AM | Location : United States







Related Discussions:- Machine and tool selection , Assignment Help, Ask Question on Machine and tool selection , Get Answer, Expert's Help, Machine and tool selection Discussions

Write discussion on Machine and tool selection
Your posts are moderated
Related Questions
Condenser ( Capacitor ) : A capacitor is used to store the electrical energy. The maximum value of stored energy depends on its capacity. It helps to achieve required high voltag

1.Calculate the heat-removal factor for a collector having an overall heat-losscoefficient of 6 W/m2K and constructed of aluminum fins and tubes. Tube-to-tube centered distance is

with the aid of a diagram explain electrochemical grinding

procedure to find resultant of several forces acting at a point

It is really significant of using a Gantt chart in order to respect the deadline of a client. Show the five main areas that must be explored for a good time management. There

Q. Illustrate Clay content test? Under this test, the clay content is measured by washing it off the sand sample. The standard dried sand sample (50 gm) is put in a mixing devi

Explain concept of Counter Bore and countersink in radial drilling machine Counter Bore :- This operation uses a pilot to guide the cutting action to accommodate the heads

Calculate the Length of Developed Blank Part shown in Figure is to be produced from flat sheet by bending operation. Calculate the length of the developed blank. Assume k = 0.

WELD DEFECTS The common defects encountered in submerged arc welding are: a. Slag inclusion b. Porosity c. Cracking of welds.   a). Slag Inclusion : Slag in

A hydraulic pipe is 20 cm internal diameter and 5 cm thick. It is needed to sustain an intensities of radial and hoop stress at several radii and plot their variation.