2341
Synthesis of multi-metal hybrid structures with narrow heat affected zones , limited residual stresses and secondary phase occurrence represents a serious scientific and technological challenge .
 heat affected zones, residual stresses, phase
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 affected zones, residual stresses, phase