Using materials common mistakes

Common mistakes

• Misunderstanding Composite Materials

  Students often confuse composite materials with pure substances, thinking they are the same.

  Fix itEmphasize that composite materials consist of a matrix or binder surrounding reinforcement fibers or fragments, while pure substances contain only one type of material.

• Misunderstanding Material Properties

  Students often confuse the properties of glass with those of clay ceramics, thinking they have similar physical characteristics.

  Fix itTo fix this, students should study the specific properties of each material, noting that glass is typically more brittle and transparent, while clay ceramics are more porous and can be shaped before firing.

• Misinterpreting density as the sole factor for material selection

  Students often think that a material’s density alone determines its suitability for a particular use, ignoring other properties such as strength, thermal conductivity or corrosion resistance.

  Fix itExplain that while density is important, other properties like mechanical strength, hardness, thermal expansion, electrical conductivity and resistance to corrosion must also be considered when matching a material to a specific application. Use examples such as aluminium alloys being chosen for aircraft parts because of their low density combined with adequate strength, not just because they are light.

• Confusing Polymer Types

  Students often confuse thermosoftening and thermosetting polymers, thinking they behave the same when heated.

  Fix itRemember that thermosoftening polymers can be reshaped when heated, while thermosetting polymers cannot be reshaped after they have set.