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Various cracking mechanisms , including solidification , liquation , strain-age , and ductility dip cracking , make it difficult to fabricate traditionally non-weldable Ni-based superalloys using the AM process .
 cracking, solidification, ductility, cracking, fabricate, superalloys, AM process
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:
 cracking, solidification, ductility, cracking, fabricate, superalloys, AM process