Ahmet Gökay Öztürk 030050143 (6th week)

Standardization

Standardization is the important step towards
interchangeable manufacture, increased output and higher economy. The technique of
standardization comprises of determining optimal manufacturing processes, identifying the
best possible engineering material, and allied techniques for the manufacture of a product and
adhering to them very strictly so long as the better standards for all these are not identified.
Thus definite standards are set up for a specified product with respect to its quality, required
equipment, machinery, labor, material, process of manufacture and the cost of production.
(R. SINGH, Introduction to Basic Manufacturing Processes and Workshop Technology, pg.6)


Metal Removal Rate


With regard to the metal removal rate, we have to distinguish between the volume
of the removed material Qw and the space needed for the randomly arranged metal
chips Qsp. The volume of the removed material identifies the volume occupied by a
chip with cross section ap· f (depth of cut multiplied with feed) and a defined length
per minute.

Qw = ap · f · vc · 10^3

Qw in mm^3/min volume of removed material
ap in mm depth of cut
f in mm feed
vc in m/min cutting speed
10^3 mm/m conversion factor for vc, from m/min to mm/min

The volume of the randomly arranged metal chips removed Qsp is greater than the
real volume of the same amount of removed material Qw, since, in a reservoir, the
chips are not located one next to one another without gaps. Chip volume ratio R
defines by what factor the volume of the randomly arranged chips Qsp is greater than
the volume of the removed material Qw.

Qsp = R · Qw

Qsp in mm^3/min volume of randomly arranged chips
Qw in mm^3/min volume of removed material

R chip volume ratio
Consequently, chip volume ratio R results from the ratio:
R =(Volume needed for randomly arranged metal chips)/(Material volume of the same amount of metal removal)
The amount of the chip volume ratio R depends on the chip shape.
(Heinz Tschätsch,Applied Machining Technology,pg.39)


Emergency Stop

All manufacturing plants with electrically powered machines and equip-
ment will have conveniently positioned emergency stop buttons. When
pushed all electrical machinery and equipment in the plant will stop. The
button is bright red and may have a bright yellow surrounding panel, and be
sited in prominent positions. This device isolates the plant at the main
switchboard, and individual machines or pieces of equipment cannot be
restarted by pressing their start buttons. All employees in the plant should
be familiar with the position of these buttons. Only an authorized person can
switch the electricity back on again.
(R . Timings, Basic Manufacturing 3rd. ed., pg.227)

Material Selection Charts

The engineering properties of materials are usefully displayed as material
selection charts. The charts summarize the information in a compact, easily
accessible way, they show the range of any given property accessible to the
designer and they identify the material class associated with segments of
that range. By choosing the axes in a sensible way, more information can
be displayed: a chart of modulus E against density ρ reveals the longitudinal
wave velocity (E/ρ)^1/2; a plot of fracture toughness K1C against
modulus E shows the toughness G1C; a diagram of thermal conductivity λ
against diffusivity, a, also gives the volume specific heat ρCv; strength, σf,
against modulus, E, shows the energy-storing capacity σ^2/E, and there are
many more.
(Michael F. Ashby,Materials Selection in Mechanical Design 3rd. ed, pg.77)