5891
The objective of this work is to detect in situ the occurrence of lack-of-fusion defects in titanium alloy ( Ti-6Al-4 V ) parts made using directed energy deposition ( DED ) additive manufacturing ( AM ) .
 in situ, defects, titanium alloy, Ti-6Al-4 V, directed energy deposition, DED, additive manufacturing, AM
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:
 in situ, defects, titanium alloy, Ti-6Al-4 V, directed energy deposition, DED, additive manufacturing, AM