4593
The results show that the specificity of the microstructure affected by the DED process and pore defects , such as segregation of Al and the existence of incomplete grain boundaries , are the main causes of crack initiation .
 concept or principle: microstructure; manufacturing process: DED; machanical property: pore; concept or principle: defects; material: as; material: Al; concept or principle: grain boundaries
Given options, please tell me the categories of all the listed entity words.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} 
 Entities: microstructure, DED, pore, defects, as, Al, grain boundaries 
Answer:
 concept or principle: microstructure; manufacturing process: DED; machanical property: pore; concept or principle: defects; material: as; material: Al; concept or principle: grain boundaries