Material selection and study of material is critical to safe and functional design . The key properties which matter should be known by the designer.
One of the first steps in selection of a material in mechanical design is understanding and differentiating the various mechanical properties.
1. Modulus – How stiff is it?
Modulus, or Young's modulus, is a measure of a material's stiffness or resistance to deformation. It is an important factor to consider in mechanical design because it determines how much a part will deflect or bend under a given load, and can influence the selection of materials and the design of the part's geometry.
2. Strength – How much stress can it take before it deforms permanently?
Strength: Strength is a measure of a material's ability to withstand a load or force without breaking or deforming. It is critical in mechanical design because it determines whether a part will be able to support the required loads and stresses without failing or deforming beyond acceptable limits.
3. Toughness- How much energy can it absorb before it fractures/ breaks?
Toughness is a measure of a material's ability to absorb energy before breaking or fracturing. It is important in mechanical design because it determines how much energy a part can absorb before it fails, and can be used to assess the risk of brittle fracture or catastrophic failure.
4. Fracture toughness – How fast do cracks propagate under fatigue loading?
It is a measure of a material's ability to resist crack propagation and failure in the presence of a pre-existing crack or flaw. Fracture toughness is typically characterized using a test called the "fracture toughness test," which involves applying a controlled amount of force to a pre-cracked specimen and measuring the resulting crack growth.
5. Hardness – How hard is it? Can any other material scratch or penetrate on the surface?
Hardness is a measure of a material's resistance to indentation or scratching. It is important in mechanical design because it can affect the wear resistance and durability of a part, and can also be used to estimate a material's strength.