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As a result , the hardness of the samples , as well as the area fraction of precipitates formed in the samples , increases gradually from top to bottom of the rod , while corrosion resistance is uniformly high throughout the rod almost independently of the location .
 As, hardness, samples, as, as, area, precipitates, samples, rod, corrosion resistance, rod
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:
 As, hardness, samples, as, as, area, precipitates, samples, rod, corrosion resistance, rod