Nanocrystalline Cu-5 wt%Cr alloy powders were fabricated by mechanical alloying （MA）, The effects of MA processing parameters on the crystallite size, solid solubility, and microstructures of the Cu- 5 wt%Cr alloys ...Nanocrystalline Cu-5 wt%Cr alloy powders were fabricated by mechanical alloying （MA）, The effects of MA processing parameters on the crystallite size, solid solubility, and microstructures of the Cu- 5 wt%Cr alloys were investigated including type and size distribution of the grinding medium and ball-topowder weight ratio （BPR）. The results show that the crystallites were refined effectively and solid solubility of Cr in Cu was extended when heavier ball and higher BPR were adopted. The maximum solubility is extended up to 5.6 at% （namely 4.6 wt%） Cr in Cu by use of a combination of large and small size WC-Co balls with BPR of 30：1. A Cn-5 wt%Cr supersaturated solid solution alloy bulk is obtained by spark plasma sintering the as-milled powders at 900 ℃ for 5 min.展开更多
Al1-xWX( x = 0.1, 0.2, 0.5, 0.9) powders have been prepared by mechanical alloying of the elements in a planetary ball mill. The structure and morphology of the milled powders were investigated using X-ray diffraction...Al1-xWX( x = 0.1, 0.2, 0.5, 0.9) powders have been prepared by mechanical alloying of the elements in a planetary ball mill. The structure and morphology of the milled powders were investigated using X-ray diffraction and electron microscopy. The solubility of Al in W is greatly extended, even more than 50% . The results are analyzed using embedded atom method (EAM) according to the scheme of mechanical alloying extending solid solubility. The theoretical results are in good agreement with the experimental.展开更多
Mechanical alloying has been performed in Ag-Cu immiscible alloy system with five different compositions. X-ray diffraction analysis was carried out to determine the structural characterization of the milled powders. ...Mechanical alloying has been performed in Ag-Cu immiscible alloy system with five different compositions. X-ray diffraction analysis was carried out to determine the structural characterization of the milled powders. Lattice constants of the milled powders were determined and the solubility for Ag in Cu was calculated. The results demonstrated that MA indeed produced a face center cubic (f.c.c.). Cu-based Cu-Ag solid solution and the solid solubility has been extended to x(Ag)=30% for Ag in Cu when the grain size of Cu-based Cu-Ag solid solution is about 10 nm after MA. There is a three-phases co-existence during the process of MA in this alloy system which agrees well with other experimental and theoretical results. Based on the experimental results a formation model was proposed in this paper to understand the formation of Ag-Cu solid solution during MA.展开更多
Mg-6Li and Mg-6Li-1Y （wt.%） alloys were prepared using permanent model casting method, and microstructure and mechanical properties were investigated by means of X-ray diffraction （XRD）, scanning electron microsco...Mg-6Li and Mg-6Li-1Y （wt.%） alloys were prepared using permanent model casting method, and microstructure and mechanical properties were investigated by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, optical microscopy （OM）, energy dis-persive spectrometry （EDS）, transmission electron microscopy （TEM）, etc. The results showed that α-Mg and ？-Li phases existed in both al-loys, and there was also Y-enriched phase in Mg-6Li-1Y alloy. The composition of Y-enriched phase was near to the maximal solid solubility of Y in α-Mg phase. The ultimate tensile strength and yield strength of Mg-6Li-1Y alloy were improved to 112 and 107 MPa, respectively. The elongation of Mg-6Li-1Y alloy was greatly enhanced to 32% at room temperature, which was about eight times as great as that of Mg-6Li alloy. The strengthening effects of Mg-6Li-1Y alloy were attributed to the solid solution effect and precipitates both introduced by Y.展开更多
基金Funded by Alstom Grid China Technology Centre and the National Basic Research Program of China (973 Program)(No.2012CB619600)
文摘Nanocrystalline Cu-5 wt%Cr alloy powders were fabricated by mechanical alloying （MA）, The effects of MA processing parameters on the crystallite size, solid solubility, and microstructures of the Cu- 5 wt%Cr alloys were investigated including type and size distribution of the grinding medium and ball-topowder weight ratio （BPR）. The results show that the crystallites were refined effectively and solid solubility of Cr in Cu was extended when heavier ball and higher BPR were adopted. The maximum solubility is extended up to 5.6 at% （namely 4.6 wt%） Cr in Cu by use of a combination of large and small size WC-Co balls with BPR of 30：1. A Cn-5 wt%Cr supersaturated solid solution alloy bulk is obtained by spark plasma sintering the as-milled powders at 900 ℃ for 5 min.
基金This work was supported by the Foundation of Educational Department Guangxi and the Special Foundation of "Ten,Hundred and Thousand Specialists in Guangxi"
文摘Al1-xWX( x = 0.1, 0.2, 0.5, 0.9) powders have been prepared by mechanical alloying of the elements in a planetary ball mill. The structure and morphology of the milled powders were investigated using X-ray diffraction and electron microscopy. The solubility of Al in W is greatly extended, even more than 50% . The results are analyzed using embedded atom method (EAM) according to the scheme of mechanical alloying extending solid solubility. The theoretical results are in good agreement with the experimental.
文摘Mechanical alloying has been performed in Ag-Cu immiscible alloy system with five different compositions. X-ray diffraction analysis was carried out to determine the structural characterization of the milled powders. Lattice constants of the milled powders were determined and the solubility for Ag in Cu was calculated. The results demonstrated that MA indeed produced a face center cubic (f.c.c.). Cu-based Cu-Ag solid solution and the solid solubility has been extended to x(Ag)=30% for Ag in Cu when the grain size of Cu-based Cu-Ag solid solution is about 10 nm after MA. There is a three-phases co-existence during the process of MA in this alloy system which agrees well with other experimental and theoretical results. Based on the experimental results a formation model was proposed in this paper to understand the formation of Ag-Cu solid solution during MA.
基金supported by the National Natural Science Foundation of China for Creative Research Group (20921002)the Foundation for Science Program of Changchun City (08YJ09)
文摘Mg-6Li and Mg-6Li-1Y （wt.%） alloys were prepared using permanent model casting method, and microstructure and mechanical properties were investigated by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, optical microscopy （OM）, energy dis-persive spectrometry （EDS）, transmission electron microscopy （TEM）, etc. The results showed that α-Mg and ？-Li phases existed in both al-loys, and there was also Y-enriched phase in Mg-6Li-1Y alloy. The composition of Y-enriched phase was near to the maximal solid solubility of Y in α-Mg phase. The ultimate tensile strength and yield strength of Mg-6Li-1Y alloy were improved to 112 and 107 MPa, respectively. The elongation of Mg-6Li-1Y alloy was greatly enhanced to 32% at room temperature, which was about eight times as great as that of Mg-6Li alloy. The strengthening effects of Mg-6Li-1Y alloy were attributed to the solid solution effect and precipitates both introduced by Y.
