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Among them , the use of stainless steels , cobalt based alloys , and titanium and its alloys are well established due to their good biocompatibility , satisfactory mechanical strength and superior corrosion resistance .
 material: stainless steels; material: cobalt; material: alloys; material: titanium; material: alloys; machanical property: biocompatibility; machanical property: mechanical strength; concept or principle: corrosion resistance
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 material: stainless steels; material: cobalt; material: alloys; material: titanium; material: alloys; machanical property: biocompatibility; machanical property: mechanical strength; concept or principle: corrosion resistance