1466
5 Current methods for quality improvement in the WAAM process Generally , WAAM parts require post-process treatment to improve material properties , reduce surface roughness and porosity , and remove residual stress and distortions .
 concept or principle: quality; manufacturing process: WAAM; concept or principle: process; manufacturing process: WAAM; concept or principle: post-process; concept or principle: material properties; machanical property: surface roughness; machanical property: porosity; machanical property: residual stress
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: 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:
 concept or principle: quality; manufacturing process: WAAM; concept or principle: process; manufacturing process: WAAM; concept or principle: post-process; concept or principle: material properties; machanical property: surface roughness; machanical property: porosity; machanical property: residual stress