To explore the approaches of combined toughening and strengthening of the Al_3Ti-based L1_2 intermetallic alloys, multiphase Al_3Ti alloys formed by combining with reinforcement or by second phase precipitation are be...To explore the approaches of combined toughening and strengthening of the Al_3Ti-based L1_2 intermetallic alloys, multiphase Al_3Ti alloys formed by combining with reinforcement or by second phase precipitation are being studied. The interface reactions between Al_(66)Fe_9Ti_(25)matrix and SiC reinforcement were investigated. It is determined that SiC is chemically incompatible with the Al_(66)Fe_9Ti_(25)matrix, Al_2O_3 barrier coating on SiC by sol-gel process was developed to minimize the interfacial reactions. On the other hand, a new type of Al_3Ti-based alloy having a L1_2 matrix with second phase precipitation has been developed. The quaternary alloys based on Al_(66)Fe_9Ti_(25)and modified with Nb additions, consist of a L1_2 matrix and D0_(22) second phase in the annealed state ,but the second phase can be dissolved by solution treatment and precipitated during high temperature aging.展开更多
Presents the investigation of as cast microstructures of high temperature α+α 2 titanium alloys matrix composites reinforced by particles and fabricated using a reaction synthesis method by XRD, OM and SEM which rev...Presents the investigation of as cast microstructures of high temperature α+α 2 titanium alloys matrix composites reinforced by particles and fabricated using a reaction synthesis method by XRD, OM and SEM which reveals that the matrix transformed into single phase α 2 from two phases α+α 2 and reinforcing phases become Ti 3AlC and TiC from single phase TiC as C content increases to a critical value, and Ti 3AlC precipitates during solidification processing and points out that the morphologies of TiC and Ti 3AlC are of short lath shape and near spherical shape, respectively, and lattice parameters of matrix α 2 increase with the increasing of C content, but the lattice parameter of reinforcing phase TiC is lower than standard lattice parameter of TiC due to the C defection in TiC.展开更多
文摘To explore the approaches of combined toughening and strengthening of the Al_3Ti-based L1_2 intermetallic alloys, multiphase Al_3Ti alloys formed by combining with reinforcement or by second phase precipitation are being studied. The interface reactions between Al_(66)Fe_9Ti_(25)matrix and SiC reinforcement were investigated. It is determined that SiC is chemically incompatible with the Al_(66)Fe_9Ti_(25)matrix, Al_2O_3 barrier coating on SiC by sol-gel process was developed to minimize the interfacial reactions. On the other hand, a new type of Al_3Ti-based alloy having a L1_2 matrix with second phase precipitation has been developed. The quaternary alloys based on Al_(66)Fe_9Ti_(25)and modified with Nb additions, consist of a L1_2 matrix and D0_(22) second phase in the annealed state ,but the second phase can be dissolved by solution treatment and precipitated during high temperature aging.
文摘Presents the investigation of as cast microstructures of high temperature α+α 2 titanium alloys matrix composites reinforced by particles and fabricated using a reaction synthesis method by XRD, OM and SEM which reveals that the matrix transformed into single phase α 2 from two phases α+α 2 and reinforcing phases become Ti 3AlC and TiC from single phase TiC as C content increases to a critical value, and Ti 3AlC precipitates during solidification processing and points out that the morphologies of TiC and Ti 3AlC are of short lath shape and near spherical shape, respectively, and lattice parameters of matrix α 2 increase with the increasing of C content, but the lattice parameter of reinforcing phase TiC is lower than standard lattice parameter of TiC due to the C defection in TiC.
