2052
The aB-printed structures were free of large-scale defects and voids , and were further characterized and compared to commercial Blackalloy 525 barstock ( B525 ) , a Co-Cr-W alloy tool of similar composition .
 concept or principle: defects; concept or principle: voids; material: alloy; concept or principle: composition
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: defects, voids, alloy, composition 
Answer:
 concept or principle: defects; concept or principle: voids; material: alloy; concept or principle: composition