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As a step forward toward the development of the next generation of nickel aluminum bronze ( NAB ) components using wire-arc additive manufacturing ( WAAM ) , square bars were printed in the vertical direction .
 As, step, nickel aluminum bronze, NAB, components, wire-arc additive manufacturing, WAAM, vertical
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:
 As, step, nickel aluminum bronze, NAB, components, wire-arc additive manufacturing, WAAM, vertical