6741
Post-treatment by LPEB irradiation removed the partially melted particles , while reflow of the molten mass filled the cracks and voids and facilitated the formation of a uniform surface with a bright metallic finish .
 Post-treatment, irradiation, melted, voids, surface, metallic
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:
 Post-treatment, irradiation, melted, voids, surface, metallic