Blog 5

Materials for design

In materials for design, we learnt that the design of a chemical product involves 3 interrelated problems:

1. Selecting a material

2. Specifying a shape

3. Choosing a manufacturing process

This selection allows us to find the optimal combination to get benefits in any engineering-based business. It leads to lower product costs, faster time-to-market and a reduction in the number of in-service failures.

Selection of materials

The objective of selection of materials is to find the most suitable material that satisfies the functional requirements of a product.

Material properties

Mechanical properties:

Strength: Yield strength, Ultimate tensile strength, shear strength

Ductility

Young's modulus

Poisson's ratio

Hardness

Creep

Temperature behaviour

Density

Anisotropy

Fracture toughness

Gas and liquids: Viscosity

Thermal properties:

Thermal expansion coefficient, Thermal conductivity, Specific heat capacity

Magnetic properties

Fabrication properties:

Ease of machining

Ease of welding/ casting, Hardening ability, Formability, Availability, Joining techniques

Environmental properties: Corrosion properties, Toxic effects

Gas and liquids: Viscosity

Environemental properties:

Corrosion properties

Polluting effect

Toxic effects

The next stage in the material selection process is choosing the most economical material

Step 1: List the material requirements (function, constraints and objectives) for the design.

Step 2: Select and evaluate candidate materials using COWS matrix.

Step 3: Choose the most economical material.

Next, we had to apply these 3 steps in CA2 report part 1, here is what my group did! We were tasked to select materials for the blade and body for a disposable safety razor for men.

Step 1:

Step 2 and 3:

Design for Materials

In design for materials, we try to break the boundaries by trying to find material with property attributes that exceeds the requirements of a product. At the same time, this cannot be too costly or too difficult to manufacture.

In class, one of the examples that were shown is the hair dryer.🦰 In the beginning, the hair dryer was really bulky, made of metal and the drying proccess took a long time. However, over the years, changes were made to the design of the hair dryer whereby it got lighter, became more efficient and overall had a much better design. Another example used was ceramic knives. 🗡

In our CA2 report part 2, we had to select a material from the SP library that appeals to us. We then had to discuss how the material can replace another material in an existing product without changing the design and how can the matereial enhance the functionalitu of the existing product through the changes in design. We decided to use imago frozen fabric because it sounded very unique. :))

Sustainable design

Sustainable design ensures that while creating products, the materials used have their environmental, social and economic impacts considered through to the end of life.♼

In part 3 of our CA2 report, we think of changes that can be made to our coffee maker to make it more environmentally sustainable. There are also a few examples provided.

-Use non-toxic, sustainably produced, or recycled materials.

-Use energy efficient processes.

-Design for reuse and recycling.

-Shift from personal ownership to shared ownership.

-Buy from nearby.

Heres what my group's ideas for sustainable design:

Reflection

My takeaway from these few lessons are that everything that we use, whether it be on a daily basis or those that we do not use that often, have a lot of thoughts behind them. Thoughts like how to make them more sustainable for the environment, or how can they better fit the role that they are being used for. It also allows me to see possible improvements in many objects that I use that can possibly be implemented.