4946
Unlike their solid counterparts , porous tantalum and the titanium-tantalum alloy had the greatest fatigue strength for a given stiffness , 8 % greater than CP-Ti and 19 % greater than Ti6Al4V ELI .
 porous, alloy, fatigue strength, stiffness, Ti6Al4V
Please list all entity words in the text that fit the category. Output format is "word1, 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:
 porous, alloy, fatigue strength, stiffness, Ti6Al4V