Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Magnesium And Its Alloys
Magnesium is a light metal along with density of 1.74 g/cm3. Magnesium is more costly than aluminium as density 2.74 g/cm3 along with which it compares for lightness. Magnesium in its molten state burns readily, thus it is complicated to cast the alloys of magnesium. Magnesium alloys contain low corrosion resistance and presents poor creep and fatigue behaviour. Their h.c. p. structure does not allow deforming readily at room temperature as only three slip systems exist in h. c. p. at room temperature. The best benefit that magnesium alloys offer is such of low density and a lot of aircraft parts are made in these alloys.
Al while added to Mg in the range of 3 to 10% along with minute amounts of Zink and Mn raises strength, castability and hardness. Addition of Mn as 1.2% along with small amount of C does not raises strength but enhances corrosion resistance. Mg-Al-Zink alloys contain good corrosion resistance and mechanical strength. Such alloys are good casting material and usually used at high temperature like 250oC. Extrusions and forgings for normal purpose are made in such alloys are utilized in aircraft, radio, instrument and automotive industries.
Several magnesium alloys are illustrated in Table no.21 with their applications.
Table no.21: Magnesium Alloys
Composition (% )
Condition
UTS N/mm2
YS N/mm2
Elongation
%
Application
Wrought alloys
Mg, 3 Al, 1 Zn, 0.2 Mn
Annealed
228
-
11
Air borne cargo equipment
Mg, 2 Th, 0.8 Mn
T8
198
6
Missile and aircraft sheets upto 427oC
Mg, 6 Zn, 0.5 Zr
T5
310
235
5
Highly stressed aerospace uses, extrusions, forgings
Cast alloys
MG, 6 Zn, 3 Al, 0.15
Mn
As-cast
179
76
4
Sand casting requiring good room temperature strength
Mg, 3 Re, 3 Zn, 0.7 Zr
T6
138
110
97
3
2
Pressure tight and permanent mould castings used at
150-260oC
Martempering: The piece to be hardened is wholly austenitized and after that quenched in a lead of salt bath held at a temperature simply above at that martensite would begin
Pneumatic system is a system that uses air to power something. For example, have you seen the tube systems at bank drive-up tellers? Air is used to drive the tubes back and forth f
Normal 0 false false false EN-US X-NONE X-NONE
Q. How to observe water level? Site for installing gauges should be properly selected. The reach should be reasonably straight and of uniform cross· section and slope. The leng
Concept of centrifugal tension: Explain concept of centrifugal tension in any belt drive. What is main consideration for taking maximum tension? Sol: T he belt continuo
(a) A geometrically similar model of spillway is to be laid to a scale of 1 in 50. Evaluate the velocity ratio, discharge ratio and acceleration ratio. (b) If model prototype ra
Q. Illustrate Brinell hardness tests? Brinell hardness tests of the deposited weld, and heat affected zone shall be required for procedure qualifications of every welding proce
A 50 mm dia. jet having a velocity of 18 m/sec. impinges without shock on a flat plate inclined at an angle to the axis of jet. If the plate is moving at 5 m/sec in the direction o
He a t: Sol: Heat can be energy transferred across the boundary of a system because of temperature difference between system and surrounding. The heat is transferred by th
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd