The influence of the RE-rich phase distribution in the precursor alloys on the anisotropy of the hydrogenation disproportionation desorption recombination（HDDR） processed powders is investigated. The homogenized ing...The influence of the RE-rich phase distribution in the precursor alloys on the anisotropy of the hydrogenation disproportionation desorption recombination（HDDR） processed powders is investigated. The homogenized ingot alloy and the as-cast strip casting（SC） alloy with a uniform RE-rich grain boundary phase lead to high anisotropy of the refined powders,acquiring degrees of alignment（DOA） of 0.62 and 0.54, respectively. The RE-rich phase aggregation results in a deteriorated DOA of the powders due to the drastic disproportionation rate, while a thin and uniform RE-rich phase distribution is beneficial for DOA. A reaction model of the initial particle microstructure is proposed for optimizing the HDDR powder anisotropy.展开更多
REE contents of water and vegetables, from two typical RE-rich background regionsand normal region in Gainan,Jiangxi Province, China, indicatethat REE contents are markedlydifferent in water and vegetables.There are a...REE contents of water and vegetables, from two typical RE-rich background regionsand normal region in Gainan,Jiangxi Province, China, indicatethat REE contents are markedlydifferent in water and vegetables.There are average 0.03 mg·L-1and 0. 11 mg·L-1 REE in water ofA and B regions. As REE contentsof vegetables for A region are different from B region, it suggeststhat there are a lot of factors controlling REE distribution betweenvegetables. Comparing with thenormal region, soluble RE contentsin water of the RE-rich backgroundregions are factors of 68 and 18than that of the normal region.REE contents of the most plantsand crops in A and B regions arehigher than that in the normal region. It is clear that REE are theindispensable elements of plantsduring their growing period. Asthere are unusually higher REEcontents of some plants in A and Bthan in the normal regions, it isconsidered to result from absorbingREE passively during the period ofplants and crops growing up.展开更多
A low-diffusion Ni Re Pt Al coating((Ni,Pt)Al outer layer in addition to a Re-rich diffusion barrier layer)was prepared on a Ni_(3)Al-base single crystal(SC)superalloy via electroplating and gaseous aluminizing treatm...A low-diffusion Ni Re Pt Al coating((Ni,Pt)Al outer layer in addition to a Re-rich diffusion barrier layer)was prepared on a Ni_(3)Al-base single crystal(SC)superalloy via electroplating and gaseous aluminizing treatments,wherein the electroplating procedures consisted of the composite deposition of Ni-Re followed by electroplating of Pt.In order to perform a comparison with conventional Ni Al and(Ni,Pt)Al coatings,the cyclic oxidation performance of the Ni Re Pt Al coating was evaluated at 1100 and 1150℃.We observed that the oxidation resistance of the Ni Re Pt Al coating was significantly improved by the greater presence of the residualβ-Ni Al phase in the outer layer and the lesser outward-diffusion of Mo from the substrate.In addition,the coating with the Re-rich diffusion barrier demonstrated a lower extent of interdiffusion into the substrate,where the thickness of the second reaction zone(SRZ)in the substrate alloy decreased by 25%.The mechanisms responsible for improving the oxidation resistance and decreasing the extent of SRZ formation are discussed,in which a particular attention is paid to the inhibition of the outward diffusion of Mo by the Re-based diffusion barrier.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.51101167)the Ningbo Natural Science Foundation,China(Grant No.2013A610075)+4 种基金the Ningbo Science and Technology Project,China(Grant No.2013B10004)the Program of International Science and Technology Cooperation of China(Grant No.2010DFB53770)the China Postdoctoral Science Foundation(Grant No.2012M520943)the State Key Program of the National Natural Science Foundation of China(Grant No.2011AA03A401)the National Key Technologies R&D Program of China(Grant No.2012BAE01B03)
文摘The influence of the RE-rich phase distribution in the precursor alloys on the anisotropy of the hydrogenation disproportionation desorption recombination（HDDR） processed powders is investigated. The homogenized ingot alloy and the as-cast strip casting（SC） alloy with a uniform RE-rich grain boundary phase lead to high anisotropy of the refined powders,acquiring degrees of alignment（DOA） of 0.62 and 0.54, respectively. The RE-rich phase aggregation results in a deteriorated DOA of the powders due to the drastic disproportionation rate, while a thin and uniform RE-rich phase distribution is beneficial for DOA. A reaction model of the initial particle microstructure is proposed for optimizing the HDDR powder anisotropy.
文摘REE contents of water and vegetables, from two typical RE-rich background regionsand normal region in Gainan,Jiangxi Province, China, indicatethat REE contents are markedlydifferent in water and vegetables.There are average 0.03 mg·L-1and 0. 11 mg·L-1 REE in water ofA and B regions. As REE contentsof vegetables for A region are different from B region, it suggeststhat there are a lot of factors controlling REE distribution betweenvegetables. Comparing with thenormal region, soluble RE contentsin water of the RE-rich backgroundregions are factors of 68 and 18than that of the normal region.REE contents of the most plantsand crops in A and B regions arehigher than that in the normal region. It is clear that REE are theindispensable elements of plantsduring their growing period. Asthere are unusually higher REEcontents of some plants in A and Bthan in the normal regions, it isconsidered to result from absorbingREE passively during the period ofplants and crops growing up.
基金the Key-Area Research and Development Program of Guangdong Province(2019B010936001)financially supported by the National Natural Science Foundation of China(Grant Nos.51671202 and 51301184)。
文摘A low-diffusion Ni Re Pt Al coating((Ni,Pt)Al outer layer in addition to a Re-rich diffusion barrier layer)was prepared on a Ni_(3)Al-base single crystal(SC)superalloy via electroplating and gaseous aluminizing treatments,wherein the electroplating procedures consisted of the composite deposition of Ni-Re followed by electroplating of Pt.In order to perform a comparison with conventional Ni Al and(Ni,Pt)Al coatings,the cyclic oxidation performance of the Ni Re Pt Al coating was evaluated at 1100 and 1150℃.We observed that the oxidation resistance of the Ni Re Pt Al coating was significantly improved by the greater presence of the residualβ-Ni Al phase in the outer layer and the lesser outward-diffusion of Mo from the substrate.In addition,the coating with the Re-rich diffusion barrier demonstrated a lower extent of interdiffusion into the substrate,where the thickness of the second reaction zone(SRZ)in the substrate alloy decreased by 25%.The mechanisms responsible for improving the oxidation resistance and decreasing the extent of SRZ formation are discussed,in which a particular attention is paid to the inhibition of the outward diffusion of Mo by the Re-based diffusion barrier.
