On the strengthening and embrittlement mechanisms of an additively manufactured Nickel-base superalloy

摘要: Abstract The γ′ phase strengthened Nickel-base superalloy is one of the most significant dual-phase alloy systems for high-temperature engineering applications. tensile properties laser powder-bed-fused IN738LC in as-built state have been shown to both good strength and ductility compared with its post-thermal treated state. A microstructural hierarchy composed weak texture, sub-micron cellular structures dislocation walls was promoted sample. After treatment, secondary precipitated various size fraction depending on heat treatment process. For room-temperature tests, dominated deformation mechanism planar slip dislocations sample while bypassing precipitates via Orowan looping samples. extraordinary strengthening effect due substructure provides an addition 372 MPa yield strength. results our calculation are agreement experimental all three different conditions investigated. Strikingly, samples higher work hardening rate than but encounter premature failure. Experimental evidence shows that embrittlement caused by high grain interior region, which reduces ability accommodate further plastic strain leads intergranular cracking. On basis these results, micromechanism double-edge discussed detail.