3480
Residual distortion is a major technical challenge for laser powder bed fusion ( LPBF ) additive manufacturing ( AM ) , since excessive distortion can cause build failure , cracks and loss in structural integrity .
 Residual distortion, laser powder bed fusion, LPBF, additive manufacturing, AM, distortion, build failure, structural integrity
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:
 Residual distortion, laser powder bed fusion, LPBF, additive manufacturing, AM, distortion, build failure, structural integrity