6772
The growth of the long columnar grains into the top layer is inhibited if the penetration depth during the remelting of a previous layer is less than the depth of the equiaxed grains .
 columnar grains, layer, penetration depth, layer, equiaxed grains
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:
 columnar grains, layer, penetration depth, layer, equiaxed grains