نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشکده مهندسی مواد، دانشگاه صنعتی اصفهان، اصفهان 83111-84156، ایران
2 دانشکده مدیریت و مهندسی تولید، دانشگاه پلی تکنیک تورین، تورین 10129، ایتالیا
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Ti-6Al-2Sn-4Zr-2Mo (Ti6242) alloy is a near-alpha titanium alloy widely used in biomedical, automobile and aviation industries, known for having a higher service temperature than the more commonly used Ti-6Al-4V alloy. This has made conventional processing of the alloy more challenging. As a result, additive manufacturing processes, particularly powder bed fusion (PBF) methods, have recently been employed to produce components from this alloy. In this study, microstructure, phases formed, and hardness of Ti6242 alloy samples produced by two powder bed fusion techniques, i.e. electron beam (EB-PBF) and laser (L-PBF), were analyzed and compared using optical microscopy, scanning electron microscopy, and X-ray diffraction. The results indicated that the porosity levels in both samples were within the acceptable ranges for powder bed fusion processes, with L-PBF showing somewhat lower porosity. The solidified microstructure of L-PBF samples consisted of columnar β grains with martensitic α' phase, and that of EB-PBF sample consisted of lamellar α+β phases with Widmanstätten and basketweave morphology and α colonies. Microstructure of EB-PBF sample near the top surface was different from that of the lower layers due to variations in the cooling rate and annealing time during deposition of the last layers. XRD pattern driven Williamson-Hall plots revealed higher lattice microstrain in the L-PBF process. The average hardness of EB-PBF and L-PBF samples was measured to be approximately 408 HV and 401 HV, which are higher than that of the hardness of conventionally fabricated components.
کلیدواژهها [English]
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