The crystallization behaviour of amorphous Al_(85)Ni_(10)Y_(5) alloy under high pressure was investigated.Results showed that the amorphous state can be preserved when the alloy is treated under high pressure at tempe...The crystallization behaviour of amorphous Al_(85)Ni_(10)Y_(5) alloy under high pressure was investigated.Results showed that the amorphous state can be preserved when the alloy is treated under high pressure at temperature below 325℃,the polytropic crystallization takes place when the alloy is treated at 325〜520 ℃ and 3〜6GPa for 1 min;the crystallizing product is nanometer scale supersaturated fee-Al solid solution particles dispersed in amorphous matrix;under 1 GPa pressure amorphous allloy crystallizes in an eutectic way,the crystallizing products are fee-Al,Al_(3)Y,Al_(3)Ni,AlNiY equilibrium crystalline phases etc.High pressure appreciably changes the crystallization mode and the products,elevates the crystallizing temperature.展开更多
Several Al-Cu-Fe-Mg powders were produced by rapid solidification.The powders are crystalline at room temperature,but start to be transformed into quasicrystals when being heated to 600℃ and almost transformed to sin...Several Al-Cu-Fe-Mg powders were produced by rapid solidification.The powders are crystalline at room temperature,but start to be transformed into quasicrystals when being heated to 600℃ and almost transformed to single icosahedral phase quasicrystals at about 800℃,and then,transformed into crystalline materials again at about 900℃.In this paper,the phase structural changes during heating,the composition range and formation characteristic of the Al-Cu-Fe-Mg quasicrystals are reported.展开更多
Al-based quasicrystalline powders were consolidated by a new technique.This paper describes the consolidation process and the properties of bulk quasicrystalline materials.The bulk,dense,full quasicrystalline samples ...Al-based quasicrystalline powders were consolidated by a new technique.This paper describes the consolidation process and the properties of bulk quasicrystalline materials.The bulk,dense,full quasicrystalline samples were obuined by means of consolidating quasicrystalline powders at superhigh pressure below their crystallizing temperature or at low temperture.At superhigh pressure,the thermal stability of the quasicrystalline powders increased,while the quasicrystalline powders containing some crystalline phases,were purified,that the crystalline phases disappeared and the amount of quasicrystalling phases increased.Besides,the consolidated materials possessed high strength and were free from flaws and Mach holes caused by shock waves;therefore,this method is better than the explosion consolidation technique.展开更多
基金Supported by the National Natural Science Foundation of China。
文摘The crystallization behaviour of amorphous Al_(85)Ni_(10)Y_(5) alloy under high pressure was investigated.Results showed that the amorphous state can be preserved when the alloy is treated under high pressure at temperature below 325℃,the polytropic crystallization takes place when the alloy is treated at 325〜520 ℃ and 3〜6GPa for 1 min;the crystallizing product is nanometer scale supersaturated fee-Al solid solution particles dispersed in amorphous matrix;under 1 GPa pressure amorphous allloy crystallizes in an eutectic way,the crystallizing products are fee-Al,Al_(3)Y,Al_(3)Ni,AlNiY equilibrium crystalline phases etc.High pressure appreciably changes the crystallization mode and the products,elevates the crystallizing temperature.
基金supported by the National Natural Science Foundation of Chinas
文摘Several Al-Cu-Fe-Mg powders were produced by rapid solidification.The powders are crystalline at room temperature,but start to be transformed into quasicrystals when being heated to 600℃ and almost transformed to single icosahedral phase quasicrystals at about 800℃,and then,transformed into crystalline materials again at about 900℃.In this paper,the phase structural changes during heating,the composition range and formation characteristic of the Al-Cu-Fe-Mg quasicrystals are reported.
基金supported by the National Natural Science Foundation of China
文摘Al-based quasicrystalline powders were consolidated by a new technique.This paper describes the consolidation process and the properties of bulk quasicrystalline materials.The bulk,dense,full quasicrystalline samples were obuined by means of consolidating quasicrystalline powders at superhigh pressure below their crystallizing temperature or at low temperture.At superhigh pressure,the thermal stability of the quasicrystalline powders increased,while the quasicrystalline powders containing some crystalline phases,were purified,that the crystalline phases disappeared and the amount of quasicrystalling phases increased.Besides,the consolidated materials possessed high strength and were free from flaws and Mach holes caused by shock waves;therefore,this method is better than the explosion consolidation technique.
