7252
After the post heat treatment of the aB-built SLM specimens , more grains nucleated around the inoculants , and Nb-rich precipitates were formed along the grain boundaries .
 heat treatment, SLM, grains, precipitates, grain boundaries
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:
 heat treatment, SLM, grains, precipitates, grain boundaries