4019
Numerous nano-sized particles of the metastable Al6Fe intermetallic phase with a mean size < 100 nm were finely dispersed in the α-Al matrix .
 particles, metastable, intermetallic
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:
 particles, metastable, intermetallic