The Research On Formation Mechanism And Microstructure Of Al-Cu-X Intermetallic Compound By Solid-liquid Reaction Ball Mill

Material or alloys based on intermetallic compounds have wide application in aerospace,machineries,metallurgy,chemical,and electronic industries,and which has developed into a new type of metal materials.Existed researchs on the preparation approaches and formation mechanisms of intermetallic compounds mainly focuses on binary intermetallic compounds,whereas the research on ternary intermetallic compounds is limited.A few research on the formation of ternary intermetallic compounds only centers on the aspects of pattern recognition and computational forecasting.Thus further research on the preparation technology,formation mechanisms,and microstructural evolution of ternary intermetallic compounds are needed.Based on research results about production of binary intermetallic compounds nanopowder by the solid-liquid reaction milling approach,the preparation process and formation mechanisms of ternary intermetallic compounds were investigaated in presnet study.i.e.using grinding ball made from Ni、Co、Mo、W and milling medium made from Al-cu based alloy melts,a systematical research on the preparation of Al-Cu-X alloy is conducted by the solid-liquid reaction milling method.Some main conlusion were shown as following:（1）Using Ni grinding ball and Al-cu alloy,milling speed of 80r/min,ball to material mass ratio of 11:1.Under the temperature of 893 K,Ni grinding ball is used to mill Al₅Cu alloy.In this process powder of both Al₄Cu₉ and Al₇Cu₄Ni are obtained.When the milling process is extended from 12 hours to 48 hours,powder of Al₇Cu₄Ni increases in mass fraction.Under the temperature of 1123 K,powder of Al₄Cu_9,Al₇Cu₄Ni,and Al₇Cu₂₃Ni are produced.As the process is extended,powder of Al₄Cu₉ and Al₇Cu₄Ni decrease in mass fraction,and the powder of Al₇Cu₂₃Ni gradually dominates.Then Ni grinding ball is used to mill AlCu alloy under the temperature of 1123 K.This process generates small quantity of Al₄Cu₉ alloy powder and Al₇Cu₂₃Ni alloy powder is the main products.The formation process of the above compound phases is:first Al₄Cu₉ phase is generated;then with the milling effect,AlCuNi phase is obtained.The flocculent powder products have nano-scale particle diameter which is 100-150 nanometer.（2）Using Co grinding ball and Al-cu alloy,the Al-Cu-Co alloy powder is obtianed.As the temperature increases and the process extend,following Al₄Cu₉ alloy powder,AlCo,Al₃Co_0.55Cu_1.45and Al₆₅Co₁₅Cu₂₀alloy powder are produced successively.When the mass fraction of Cu increases to 54%,Al₄Cu₉ begins to decrease in the products and the mixture of Al₃Co_0.55Cu_1.45and Al₆₅Co₁₅Cu₂₀0 starts to dominate.The products of Al-Cu-Co solid-liquid reaction milling follows such process:first,Co and Al-Cu react to generate AlCo and Al₄Cu_9;and then,Al₄Cu₉ and AlCo react to form Al-Cu-Co alloy.（3）Using Mo grinding ball and Al-cu alloy,in early stages mixture of Al₄Cu₉ and Al₅CuMo₂ compounds are produced.As the temperature increases and the process extend,the single compound of Al₅CuMo₂ alloy powder is generated.Al₅CuMo₂ alloy powder has a particle size of 200 nanoparticle with a grain size of 15 nm.The reaction process is:first Al and Mo react to generate the compound of Al-Mo;then the compound of Al-Mo and the compound of Al-Cu react to produce the ternary Intermetallic Compound of Al-Cu-Mo.（4）Using W grinding ball and Al-cu alloy,in early stages the mixture of Al₄Cu₉ and Al₅CuW₂ is produced.As the temperature increases and the process extends,the single compound of Al₅CuW₂ alloy powder is generated.Al₅CuW₂ alloy powder has a particle size of 200 nanoparticle with a grain size of 15 nm.（5）In the process of using solid-liquid reaction milling approach to produce Al-Cu-Al-Cu-X alloy,the production of Al-Cu-X alloy with different nano-scale particle size is controllable by the selection of preparation methods and grinding ball materials.