The effects of additions of Ti and W on microstructure and mechanical properties of rapidly solidified Al-Fe-V-Si alloys were investigated. Alloy powders were produced by the centrifugal rotary atomization process. Af...The effects of additions of Ti and W on microstructure and mechanical properties of rapidly solidified Al-Fe-V-Si alloys were investigated. Alloy powders were produced by the centrifugal rotary atomization process. After atomization, powders were screened to various mesh sizes to see the effect of powder size on the mechanical properties.These Powders were consolidated into billets using conventional powder metallurgy process, and then extruded into bar form.Microstructural analysis shows that the W addition results in the heterogeneous microstructure.On the other hand, the Ti addition refines the microstructure.Alloy containing both Ti and W has the highest thermal stability of the dispersoid. These variations in the microstructure are well reflected in the mechanical properties in that the Ti containtng alloys (with or without W) have the higher strength and ductility than the W containing alloy. It also shows that the alloys made of the coarser powders have better combinations of strength and ductility than those made of the finer powders.展开更多
This study investigated the microstructures and mechanical properties of ZK60 alloy prepared by a simplified rapid solidification powder metallurgy （RS P/M） processing system （S-RS P/M）, which consists of warm pre...This study investigated the microstructures and mechanical properties of ZK60 alloy prepared by a simplified rapid solidification powder metallurgy （RS P/M） processing system （S-RS P/M）, which consists of warm press in dry air and hot extrusion. Microstructure characterizations showed that S-RS P/M alloy consisted of magnesium matrix and oxide stringers of ~1 #m in width. TEM （transmission electron microscopy） observations illustrated nano-size magnesia particles （10-30 nm） constituted oxide stringer in detail. Due to a relatively higher volume of nano-size magnesia particle produced during S-RS P/M process, 0.2% yield strength of S-RS P/M ZKO0 alloy was found to be as high as 382 MPa, which is 10% higher than that of RS P/M alloy. The improvement in mechanical properties is mainly attributed to the combination effects of Orowan mechanism and coefficient of thermal expansion （CTE） mismatch because of the approximately same average grain size.展开更多
Bascd on serires authors study ofAl—Li alloys in recent years,the formation theory of powders,characteristics,powder compaction,the microstructures and the mechanical behaviors of RSP Al-Li based alloys analyzed and ...Bascd on serires authors study ofAl—Li alloys in recent years,the formation theory of powders,characteristics,powder compaction,the microstructures and the mechanical behaviors of RSP Al-Li based alloys analyzed and discussed in this paper.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
文摘The effects of additions of Ti and W on microstructure and mechanical properties of rapidly solidified Al-Fe-V-Si alloys were investigated. Alloy powders were produced by the centrifugal rotary atomization process. After atomization, powders were screened to various mesh sizes to see the effect of powder size on the mechanical properties.These Powders were consolidated into billets using conventional powder metallurgy process, and then extruded into bar form.Microstructural analysis shows that the W addition results in the heterogeneous microstructure.On the other hand, the Ti addition refines the microstructure.Alloy containing both Ti and W has the highest thermal stability of the dispersoid. These variations in the microstructure are well reflected in the mechanical properties in that the Ti containtng alloys (with or without W) have the higher strength and ductility than the W containing alloy. It also shows that the alloys made of the coarser powders have better combinations of strength and ductility than those made of the finer powders.
文摘This study investigated the microstructures and mechanical properties of ZK60 alloy prepared by a simplified rapid solidification powder metallurgy （RS P/M） processing system （S-RS P/M）, which consists of warm press in dry air and hot extrusion. Microstructure characterizations showed that S-RS P/M alloy consisted of magnesium matrix and oxide stringers of ~1 #m in width. TEM （transmission electron microscopy） observations illustrated nano-size magnesia particles （10-30 nm） constituted oxide stringer in detail. Due to a relatively higher volume of nano-size magnesia particle produced during S-RS P/M process, 0.2% yield strength of S-RS P/M ZKO0 alloy was found to be as high as 382 MPa, which is 10% higher than that of RS P/M alloy. The improvement in mechanical properties is mainly attributed to the combination effects of Orowan mechanism and coefficient of thermal expansion （CTE） mismatch because of the approximately same average grain size.
文摘Bascd on serires authors study ofAl—Li alloys in recent years,the formation theory of powders,characteristics,powder compaction,the microstructures and the mechanical behaviors of RSP Al-Li based alloys analyzed and discussed in this paper.
基金Natural Science Foundation of China(No.51871244)Hunan Provincial Innovation Foundation for Postgraduate,China(No.CX20200172)Fundamental Research Funds for the Central Universities of Central South University,China(No.1053320190103)。
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.
