【摘 要】
：
Uniaxial tensile tests and stress-controlled low-cycle fatigue (LCF) and creep-fatigue interaction (CFI) tests of Inconel 625 alloy manufactured by selective laser melting (SLM) were performed at 815 ℃ in air environments.The microstructure was characteri
【机 构】
：
School of Aircraft Engineering, Nanchang Hangkong University, Nanchang 330063, China;Jiangxi Key Lab
论文部分内容阅读
Uniaxial tensile tests and stress-controlled low-cycle fatigue (LCF) and creep-fatigue interaction (CFI) tests of Inconel 625 alloy manufactured by selective laser melting (SLM) were performed at 815 ℃ in air environments.The microstructure was characterized by optical microscopy and scanning electron microscopy after testing.The results confirmed that significant embrittlement and large scatter in LCF life are resulted from manufacturing defects.The CFI life is decreased sharply to approximately dozens of cycles with the accumulated creep strain;however,the selected dwell time (i.e.,60 s and 300 s) exhibits low sensitivity to the fracture time and elongation to failure.The embrittlement of SLM Inconel 625 was proposed to be due to the low grain uniformity and precipitation of carbides at the grain boundaries.Due to the quality of the SLM process,the accelerated initiation and propagation of fatigue crack are caused by the present unmelted powder particles,which result in the large dispersion of LCF life.Meanwhile,due to the accumulation of creep damage,cracks in the CFI test are initiated along the grain boundaries and then linked together,contributing to a significant decline in fatigue life.
其他文献
T6-treated 20 wt％ B4Cp/6061Al sheets were joined under welding speeds of 400-1200 mm/min by friction stir welding (FSW) with a threaded cermet pin.The macro-defect-free FSW joints could be achieved at high welding speeds up to 1200 mm/min,but larger plung
W-Y2O3 composite nanopowders prepared via wet chemical method exhibit unique morphologies and microstructures.The yttrium addition during chemical reaction process affects not only the composition of tungsten acid hydrate precursors,but also the reduction
In this work,the influence of the Zener-Hollomon (Z) parameter on the microstructure and mechanical properties of copper subjected to friction stir welding (FSW) was investigated.Liquid N2 cooling was conducted to control the cooling rate after the FSW.Th
X80 pipeline steel plates were friction stir welded (FSW) under air,water,liquid CO2 + water,and liquid CO2 cooling conditions,producing defect-free welds.The microstructural evolution and mechanical properties of these FSW joints were studied.Coarse gran
AA6005A-T6 aluminum hollow extrusions were friction stir welded at a fixed high welding speed of 2000 mm/min and various rotation speeds.The results showed that the heat-affected zone (HAZ) retained the similar grain structure as the base material except
High electromagnetic shielding performance was achieved in the Mg-9Li-3Al-lZn alloy processed by accumulative roll bonding (ARB).The microstructure,electromagnetic interference shielding effectiveness (SE) in the frequency of 30-1500 MHz and mechanical pr
In order to study the effect of friction stir welding (FSW) on corrosion resistance of Al-Cu-Li alloy AA2099-T8,the microstructure and microhardness of FSW joints were characterized,and then,the corrosion behavior of the FSW joints was investigated by the
Dissimilar welded joints of reduced activation ferritic/martensitic (RAFM) steel and 316L austenitic stainless steel were prepared by friction stir welding with different butt joining modes and welding parameters.The weld quality of the joint was improved
Effects of long-term thermal exposure on γ\'particles evolution and impact toughness in the weld joint of Nimonic 263 (N263) superalloy were deeply studied at 750 ℃.Results showed that the precipitates in the weld metal were mainly composed of fine γ\
Friction stir processing (FSP),as a new kind of severe plastic deformation technique,can refine and homogenize the microstructure of metallic material.In this study,the effect of FSP on the microstructure and mechanical properties of pure Zr was investiga