Assignment 4
Material Selection
Objetcive
Use the "CES material selection software" to select the material for the following three Products:
​
1.Electric Plug
2.Coffee Mug
3.Mobile phone cover
1. Electric Plug
Concerned Properties:
Electrical conductivity
The Material should be an Insulator or atleast a bad conductor of electricity, in order to prevent the user from an unexpected electric shock.
Impact Resistance
Should be able to withstand some considerable amount of shock, which can be due to some accidental drop or collision with some objects.
Melting Point
Should not melt on application of heat upto a certain temperature.
Maximum Service Temperature
Should be able to withstand the temperature of spark generated in case of short circuit
Thermal Conductivity
Should be a poor conductor of heat so as not to transfer the heat (generated due to loss of energy while the current flows) to the hands of user.
Stage 1.
The plot between Maximum Servise Temperature and Thermal Conductivity
Stage 2.
The plot between Electrical Conductivity and Toughness.
Stage 3.
Selecting the Insulators
As a result, Polyethylene Terepthalate PET, was chosen as it offers insulating properties along with a good ability to withstand the impact. Also it can be easily mouldes.
Manufacturing
PET can be mass produces in the moulding process using Injection moulding method.
2. Coffee Mug
Concerned Properties:
Density
The Material should be light weight so as not to cause fatigue in the holding hands.
Thermal Conductivity
Should be a poor conductor of heat so as not to transfer the heat to the hands of user, and to the environment, so that the liquid remains hot for a longer time
Maximum Service Temperature
Should be able to withstand the temperature of hot beverages, which can be upto 100 degree celsius (212'F).
Impact Resistance
Stage 1.
Should be able to withstand some considerable amount of shock, which can be due to some accidental drop or collision with some objects.
The plot between Density and Thermal Conductivity
Stage 2.
The plot between Young's Modulus and elongation, Because these properties define the Deep Drawability of a metal when it is processed through a sheet metal forming process.
Stage 3.
The plot between Maximum service temperature and Toughness.
As a result Stainless steel was chosen, as it offers poor thermal conductivity, and a good extent of working temperature. Also it has a better strength as compared to plastics. Stainless steel offers a good Elongation (70%) and higher range od Young's modulus, which makes it easily drawable (Deep Drawing) for manufacturing.
Manufacturing Process
Stainless steel Coffee mugs can be mass produces by using Deep Drawing Sheet metal forming process
​in which a sheet metal blank is radially drawn into a forming die by the mechanical action of a punch. It is thus a shape transformation process with material retention. The process is considered "deep" drawing when the depth of the drawn part exceeds its diameter.
1. Punch
​
2. Die Plate
​
3. Stripper Plate
3. Mobile Phone Cover
Concerned Properties:
Density
The Material should be light weight so as not to cause fatigue in the holding hands.
Thermal Conductivity
Should not be a bad conductor of heat, so that it can transfer the heat to environment and keeps the device cool when it gets hot.
Elastic Limit
Should be elastic enough so that it can be easily ejected from the mould, and can be easily applied to the body of mobile phone,
Impact Resistance
Should be able to withstand and absorb the shock, and does not transmit the impact to the body of mobile phone.
Stage 1.
The plot between elongation and elastic limit.
Stage 2.
The plot between Density and Thermal Conductivity
As a result Polycarbonate was chosen because it is lightweight and offers, a considerable amount of thermal conductivity, good impact strength and a better grip.
Manufacturing Process
Polycarbonate mobile phone covers can be mass produced using injection moulding process.
