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Laser sintered aluminum alloys produced by metal 3D printers can replace cast aluminum alloys in aerospace , defense , and marine industries by offering better mechanical properties , less porosity , and competitive fatigue characteristics .
 Laser, aluminum alloys, metal, 3D printers, cast aluminum alloys, aerospace, marine industries, mechanical properties, porosity, fatigue
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:
 Laser, aluminum alloys, metal, 3D printers, cast aluminum alloys, aerospace, marine industries, mechanical properties, porosity, fatigue