906
After determining a suitable process window for metallurgically bonded patches without cracks and pores , investigations were carried out on the microstructure and mechanical properties of reinforced samples .
 concept or principle: process; machanical property: pores; concept or principle: microstructure; concept or principle: mechanical properties; concept or principle: reinforced
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: 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:
 concept or principle: process; machanical property: pores; concept or principle: microstructure; concept or principle: mechanical properties; concept or principle: reinforced