965
To shed light on this interesting phenomenon , this paper first discusses the mechanism of bubble formation in the melt pool and possible trapping during the solidification , and then formulates a predictive model for porosity in this regime .
 mechanism, melt pool, solidification, predictive model, porosity
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:
 mechanism, melt pool, solidification, predictive model, porosity