問題一覧
1
Primary aircraft structure (skin and spars etc.)
made of C-110M titanium
2
The melting point of titanium is
1668˚C
3
For aluminum alloy, the maximum time between removal from heat treatment furnace and quenching must be not more than
7 Seconds
4
The heat treatment of clad aluminum alloys must not be carried out more than
three (3) times
5
The Bayer process to convert
bauxite to alumina
6
Aluminium Solution heat treating is
the process of heating aluminium at prescribed temperature for a prescribed time and then cooling rapidly usually by quenching in water.
7
Duralumin
2000 series of aluminum alloy
8
Quenching is required to be done in hot or boiling water
to reduce quenching stress
9
The mechanical properties of pure aluminium are
silvery white metal which is soft and ductile.
10
Clad aluminum alloy (alclad)
5% of alloy thickness
11
The ‘Nimonic’ series of alloys are
high temperature , corrosion resistance alloys
12
The two classes of aluminum alloy is done to
Wrought (worked) and Cast (moulded)
13
Precipitation heat treatment of aluminum alloy is done to
speed up age hardening process
14
The purpose of rivets Refrigeration
to make rivets the soft formable condition
15
Adding other elements to aluminum alloys , such as copper ,manganese or magnesium
decrease corrosion resistance of the aluminum
16
The 6000 series of aluminum alloy principle alloying element of
magnesium and silicon
17
A salt bath is a heated tank containing mineral salts , typically
90% nitrate and 10% sodium nitrate
18
The identification No. of zinc in aluminum alloy is
7
19
Refrigeration of heat-treated aluminum alloys is sometimes done in order to
delay the precipitation process
20
Following solution treatment aluminum alloy can be placed into service
after 5 days.