We prepare Pd_(40.5)Ni_(40.5)P_(19) glassy samples with purified ingots by copper mold casting at a high cooling rate and by water quenching at a low cooling rate.Both of them exhibit different supercooled liquid regi...We prepare Pd_(40.5)Ni_(40.5)P_(19) glassy samples with purified ingots by copper mold casting at a high cooling rate and by water quenching at a low cooling rate.Both of them exhibit different supercooled liquid regions and multiple glass transition characteristics in their differential scanning calorimetric curves.The plasticity of the glassy sample prepared by copper mold casting is about 5%while that prepared by water quenching is almost zero(0.2%),indicating that cooling rate has influenced the plasticity of glassy alloys.By using high resolution TEM image analysis,it is revealed that there exist characteristic regions with different contrasts in the full glassy samples.The characteristic size is about 20–40nm for the glassy sample prepared by water quenching and 2–4nm for the one prepared by copper mold casting.The large difference in the plasticity of the glassy samples prepared by different cooling rates is believed to be related to the difference in the size of the characteristic nanoscale structures.The results indicate that adjusting cooling rate in preparation of glassy samples could modify the thermal and mechanical properties of the glassy alloys.展开更多
The effect of atomic oxygen(AO) on the surface oxidation of several typical Cu-based bulk metallic glasses(BMGs) was studied in the present work.The AO source using in this study is generated by discharge plasma type ...The effect of atomic oxygen(AO) on the surface oxidation of several typical Cu-based bulk metallic glasses(BMGs) was studied in the present work.The AO source using in this study is generated by discharge plasma type ground simulation equipment.The AO erosion/oxidation resistances of the amorphous alloy samples were assessed based on the analysis of mass loss,surface color and microstructure.It is found that these Cu-based BMGs possess good AO erosion/oxidation resistance and their resistance to AO erosion/oxidation strongly depends on the chemical composition.For the samples containing more Ag and/or Cu,the AO erosion/oxidation resistance is weaker.The present result is important for designing new metallic glasses using as space materials.展开更多
基金by the National Basic Research Program of China under Grant No 2007CB613905the National Natural Science Foundation of China under Grant Nos 50671050 and 50971073。
文摘We prepare Pd_(40.5)Ni_(40.5)P_(19) glassy samples with purified ingots by copper mold casting at a high cooling rate and by water quenching at a low cooling rate.Both of them exhibit different supercooled liquid regions and multiple glass transition characteristics in their differential scanning calorimetric curves.The plasticity of the glassy sample prepared by copper mold casting is about 5%while that prepared by water quenching is almost zero(0.2%),indicating that cooling rate has influenced the plasticity of glassy alloys.By using high resolution TEM image analysis,it is revealed that there exist characteristic regions with different contrasts in the full glassy samples.The characteristic size is about 20–40nm for the glassy sample prepared by water quenching and 2–4nm for the one prepared by copper mold casting.The large difference in the plasticity of the glassy samples prepared by different cooling rates is believed to be related to the difference in the size of the characteristic nanoscale structures.The results indicate that adjusting cooling rate in preparation of glassy samples could modify the thermal and mechanical properties of the glassy alloys.
基金supported by the National Basic Research Program of China(2007CB613905)the National Natural Science Foundation of China(50971073 and 51101090)
文摘The effect of atomic oxygen(AO) on the surface oxidation of several typical Cu-based bulk metallic glasses(BMGs) was studied in the present work.The AO source using in this study is generated by discharge plasma type ground simulation equipment.The AO erosion/oxidation resistances of the amorphous alloy samples were assessed based on the analysis of mass loss,surface color and microstructure.It is found that these Cu-based BMGs possess good AO erosion/oxidation resistance and their resistance to AO erosion/oxidation strongly depends on the chemical composition.For the samples containing more Ag and/or Cu,the AO erosion/oxidation resistance is weaker.The present result is important for designing new metallic glasses using as space materials.
