1997
Owing to the natural excellent corrosion resistance of Ti-6Al-4V , the obtained results revealed that the HIP process has only a slight positive effect on the corrosion resistance of Ti-6Al-4V produced by EBM .
 corrosion resistance, Ti-6Al-4V, HIP, corrosion resistance, Ti-6Al-4V, EBM
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:
 corrosion resistance, Ti-6Al-4V, HIP, corrosion resistance, Ti-6Al-4V, EBM