Final answer:
Cobalt chromium alloy used in medical implants can experience shrinkage, leading to irregularities and porosities, due to the differences in expansion coefficients when bonding with other materials. Researchers aim to find coatings with similar expansion coefficients to reduce thermal stress and improve bonding. This challenge is not exclusive to medicine; it is observed in structures and materials exposed to varying temperatures.
Step-by-step explanation:
Cobalt chromium is a metal alloy widely used in medical applications, including hip and knee implants. One of the challenges with using cobalt chromium and other metals in medical implants is that they can undergo shrinkage during the cooling process post-manufacturing. Such shrinkage can cause irregularities and porosities within the metal, potentially leading to implant failure or the necessity for replacement over time.
Shrinkage in metal alloys is an important consideration, particularly when it relates to the interface between two materials with different expansion coefficients. Similar expansion coefficients are desirable to minimize thermal stress and avoid issues such as cracks or irregular bonding. In the quest for better medical implants, researchers are seeking coatings for metals like cobalt chromium that will bond more effectively with bone and reduce the likelihood of implant rejection or failure.
The topic of thermal stress isn't limited to medical applications; it is an issue that affects various materials and structures, including everyday examples like dental fillings. Professionals in the field of materials engineering continue to research and develop solutions that offer improved compatibility and performance for implants and other applications where metal-to-bone or metal-to-other material interfaces are critical.