Candidate:
The manufacturing of orthopedic implants involves several steps. One of the primary steps is casting, which involves pouring molten metal into a mold to form a specific shape. Another critical step is alloying, which is the process of altering the properties of pure metal by adding small amounts of other elements. Cobalt is added for stiffness, while nickel and chromium are added for corrosion resistance
Candidate:
Defects in orthopedic implants can arise due to various reasons. Grain boundaries, which are weak areas between crystals, can cause issues. Dislocations are defects within the crystals that can propagate along grain boundaries. Cracks can also propagate along grain boundaries. However, the presence of other elements at the boundaries can help stop propagation.
Candidate:
Work hardening, also known as strain hardening or cold working, is the process of repeatedly loading a material tensilely, causing plastic deformation and increasing the density of dislocations. This process results in a change in grain shape and reduces voids. The dislocation-dislocation interactions make it harder for further movement and increase the strain energy. Rolling at room temperature shifts the stress-strain curve to the left, increasing stiffness and brittleness. The recrystallisation temperature is the temperature at which the deformed grains due to the working process are replaced by defect-free grains in the metal.
Candidate:
Annealing is the process of heating a cold-worked material to just below melting temperature. This process breaks the dislocations, and subsequent cooling allows recrystallization with reforming of crystal bonds. This shifts the stress-strain curve to the right and increases the material’s ductility.
