684
The fusion zone was composed of B2 + O laths after HT1 , and B2 + intergranular α2 + transformed O + primary O + acicular O after HT2 .
 concept or principle: fusion zone; material: O; material: O; material: O; material: O
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: fusion zone; material: O; material: O; material: O; material: O