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Built Ti-6Al-4 V specimens were evaluated regarding their microstructure , hardness , tensile strength , notch toughness , chemical composition and porosity , demonstrating the importance of a stable atmospheric control .
 material: Ti-6Al-4 V; concept or principle: microstructure; machanical property: hardness; machanical property: tensile strength; engineering feature: notch; concept or principle: chemical composition; machanical property: porosity
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: Ti-6Al-4 V, microstructure, hardness, tensile strength, notch, chemical composition, porosity 
Answer:
 material: Ti-6Al-4 V; concept or principle: microstructure; machanical property: hardness; machanical property: tensile strength; engineering feature: notch; concept or principle: chemical composition; machanical property: porosity