6.2 Flashcards
level 1 questions
what is a non ferrous metal
non magnetic metal that do not have iron as the base
why is pure aluminium not used
it doesn’t have sufficient strength
what ore does aluminium come from
bauxite ore
what are the most common alloying agents for aluminium
copper, magnesium, manganese, zinc
what is wrought aluminium
alloy that has been worked on mechanically
what is the 1st digit identifying for wrought alloys
major alloying element
what is the 2nd digit identifying for wrought alloys
alloying modification
what are the last 2 digits identifying for wrought alloys
nothing they are just identifying within a group
what are the 2 most common wrought alloys
2024 and 7075
what is a clad aluminium alloy
alloy with a thin layer of pure aluminium surrounding it to protect against corrosion it is applied during the rolling process at low temperatures
what is magnesium and what is the most popular type used
a light weight non metallic metal most common is AZ31
what features does titanium and its alloys have
lightweight and very strong
how is titanium corrosion resistant
thin layer of titanium oxide
what are the features of alpha alloys
medium strength, can be welded and used in forging
what are the features of alpha beta alloys
medium strength, generally not weldable, good forming characteristics
what are the 2 most common nickel alloys
monel and inconel
where is monel found
in gears and other parts that need high strength and toughness
where is Inconel found
similar places to stainless steel
what are copper and its alloys used for and why
electrical wiring because they are excellent thermal and electrical conductors
why are clad materials limited to 3 reheats
otherwise the clad will mix with the core
what are the two main classes for aluminium alloys
wrought and cast
what is 1000 series for aluminium
pure aluminium
what is the 2000 series’ principal alloying agent
copper,
what is the 3000 series’ principal alloying agent and characteristics
manganese, generally considered non heat treatable
what is the 4000 series’ principal alloying agent and characteristics
silicon, lowers metal’s melting temperature
what is the 5000 series’ principal alloying agent and characteristics
magnesium, good welding and corrosion resistant characteristics
what is the 6000 series’ principal alloying agent and characteristics
silicon and magnesium, makes metal heat treatable
what is the 7000 series’ principal alloying agent and characteristics
zinc, high tensile strength
what is the 8000 series’ alloying agent
small amounts of alloying elements such as iron lithium and nickel
what is the 9000 series for
alloys that are unassigned at the moment
what are 2 negatives to using magnesium
very reactive and highly susceptible to corrosion
what does AZ31 mean in terms of magnesium alloy
the main alloying elements are aluminium and zinc and its 3%Al and 5%Zn
what are the features of beta alloys
medium strength, excellent forming characteristics and have large quantities of high density alloying elements
what are the three most used copper based alloys
brass, bronze and beryllium
what are the two heat treatments used on aluminium
solution heat treatment and precipitation heat treatment
what is solution heat treatment
process of heating aluminium alloy to allow alloying element to mix with base metal
what happens once the aluminium alloy has been sufficiently heated in a solution heat treatment
it is then quenched in cold water and must be done within 10 seconds
For large forging using solution heat treatment why is hot water quenching essential
hot water minimises distortion and alleviates cracking
what is precipitation heat treatment
heated and when removed usually soft but hardens with ageing
what is the difference between natural aged alloys and artificial aged alloys
natural aged alloys return to full strength in room temperature and artificial need to have thermal treatment to return to full strength
what is the difference in annealing between steel and aluminium
aluminium must be cooled at a rate of 25C an hour until 260C then the rate doesn’t matter
what does T mean for alloy temper designations
alloy underwent a solution heat treatment
what does T3 mean for alloy temper designations
alloy underwent a solution heat treatment followed by strain hardening
what does T4 mean for alloy temper designations
alloy underwent a solution heat treatment followed by natural ageing
what does T6 mean for alloy temper designations
alloy underwent a solution heat treatment followed by artificial ageing
