1454
To control porosity , the following methods can be adopted : an AC GMAW-based process or CMT-PADV based process is preferred , especially for aluminum ; the highest quality shielding gas , tight gas seals , non-organic piping and short pipe lengths are highly recommended ; the wire and substrate surfaces are as clean as possible before fabrication ; high quality feedstock should be used ; the deposited bead shape needs to be optimized ; the thermal profile during processing should be monitored and controlled ; post-deposition treatment , such as interpass rolling can be applied .
 machanical property: porosity; material: be; concept or principle: process; concept or principle: process; material: aluminum; concept or principle: quality; concept or principle: gas; concept or principle: gas; material: substrate; material: as; material: as; manufacturing process: fabrication; concept or principle: quality; material: feedstock; material: be; process characterization: deposited bead shape; material: be; concept or principle: thermal profile; material: be; material: as; manufacturing process: rolling; material: be
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:
 machanical property: porosity; material: be; concept or principle: process; concept or principle: process; material: aluminum; concept or principle: quality; concept or principle: gas; concept or principle: gas; material: substrate; material: as; material: as; manufacturing process: fabrication; concept or principle: quality; material: feedstock; material: be; process characterization: deposited bead shape; material: be; concept or principle: thermal profile; material: be; material: as; manufacturing process: rolling; material: be