Flashcards in Metal Manufacturing Processes Deck (67)
What is planishing?
Giving a final finish to metal by hammering or rolling to produce a smooth surface.
What is normalising?
A heat treatment applied to steels to make the material stronger and tougher.
Give four example of heat treatments.
What is annealing?
A process to reverse the internal stress caused by work hardening.
Describe the process of annealing.
-The material is heated to a temperature at which the crystals grow.
-The material is "soaked" at this temperature.
-The material is then cooled very slowly.
What is hardening?
A process that involves heating metal to a high temperature followed by rapid cooling.
What is tempering?
A process carried out after hardening to remove brittleness.
What happens to hardness and toughness as the tempering temperature increases?
-Hardness is reduced
-Toughness is increased
What colour will steel go at a low tempering temperature?
What colour will steel go at a high tempering temperature?
Give a use of steel that has been tempered at a low temperature.
Give a use of steel that has been tempered at a high temperature.
What is quenching?
The rapid cooling of a metal following heat treatment.
Give four examples of quenching media.
What is the softest quenching medium?
What is the harshest quenching medium?
What is age hardening?
A process in which aluminium and copper alloys are left for a period of time in which the material becomes stronger and harder.
What is case hardening?
A process by which carbon is added to the outer skin of steel which can then be hardened.
Describe the process of case hardening by carburising.
-The component is placed in a carbon rich ceramic box.
-The atmosphere temperature is increased to 760° so the carbon atoms can enter the material's structure.
Give two examples of case hardening.
Give two advantages of case hardening.
-Steels that don't have sufficient carbon for heat treating can be hardened.
-The process leaves a tough inner core.
Give a disadvantage of case hardening.
Grain growth occurs requiring the need for machining.
Give five advantages of nitriding.
-No additional hardening is necessary.
-It removes the chance of cracking
-Increased resistance to corrosion.
-Economical for large numbers
Give two disadvantages of nitriding.
-High setup costs
-Potential for permanent loss of hardness.
Give two advantages of flame and induction hardening.
-Localised areas of the product can be hardened.
-Grain growth doesn't occur.
Give four examples of wasting processes.
-Sawing and filing
-Drilling and milling
-Grinding and sanding
-Blanking and piercing
Give three examples of addition processes.
-Bolts and screws
What are the four main types of redistribution processes?
Give two examples of casting.