HS2440 Week 2 Asyn_Structure of Metals (copy) Flashcards
1
Q
Structure of metals
A
- Not completely full outer orbits, often nearly empty
- they want to lose electrons, to become more stable
- forming positively charged ions
- electron loss is oxidation
- and gain is reduction
2
Q
Examples of metal ions
A
3
Q
How metallic ions form compounds (metal ores)
A
- Oxygen gains two electrons to form a negative ion
- the copper loses two electrons to become more stable and has bonded with the oxygen
- balancing charges between each-other- distinct packing patterns
- ## forming a balanced charge of negatives and positives
4
Q
different formations and packing patterns of compounds
A
- depending on the size of the ions
- and the number of different atoms packed together
- the lowest energy state systems for the ions involved
- ionic state of metals and non metals
5
Q
production of metals (through reduction in a blast furnace)
A
- carbon monoxide picks up oxygen from the metal, producing carbon dioxide and a metal
- it changes back into its higher energy metallic state (from its ionic state)
- The metallic state is inherently unstable and reverts to an ion
- corrosion is a metal going from an unstable metallic state to a stable ionic state, it produces oxides
6
Q
Properties of metals: Corrosion
A
7
Q
properties of metals: Conductivity
A
- outer electrons loosely held, because the atom is unstable
8
Q
structure of metal as it cools down
A
- as a metal cools it is variable, due to different temperatures of areas of the mold
- grain growth, or crystals growing from the outside inwards
- called dendrites
- growth at the coolest point of the crystal, branching off
- as they cool, crystals crash into eachother and create boundaries
- alloys, some metals are very soluble in others, depending on the size of atoms
- ## as they cool, temperature controls the composition of alloys of different metals
9
Q
metallography
A
- different structure, depending on if metal was cooled quickly or slowly
- ## can be seen under a microscope
10
Q
grain structures effect on metal properties
A
- grain structures affect many properties of metals, including their flexibility
- metals in alloys have different cooling and melting points
- meaning as the alloy cools, one becomes solid quicker
- creating different compositions of grains in an alloy, as they separate out some being compositions of both
- heterogeneous mixture of grains of different metals
11
Q
metals are rarely pure
A
12
Q
Manufacturing metal
A
- ## mould temperature will effect structure eg. dendrites
13
Q
Pictures of the alloy process
A
14
Q
Structures of alloys (eg interstitial, substatutional)
A
15
Q
Different alloys and their components
A
16
Q
Alloys – copper in antiquity
A
