Microstructure And Mechanical Properties Of Zirconium Matrix Composites In Situ Synthesized Carbide

Zr based alloy with excellent nuclear properties and appropriate biologicalcompatibility have been widely used in nuclear materials and medical materials formany years. However, mechanical properties and corrosion resistance of Zr are poor,those performances constraint on Zr in spacecraft applications. In this paper, on thebasis of Zr₅₀Ti₅₀alloy, study of forming mechanism and the corresponding mechanicalproperties of Zr which is added carbon and carbide particles has been came out. Alsothe subsequent heat treatment test hane been performed.Zr matrix composite materials with different content of C particles are prepared.Rolling state of Zr matix composite material with high tensile strength when thecontent of C upon0.2at%.its tensile strength and stretch rate are1171MPa and4.56%.ZrC phase is detected in the matrix when the content of C is0.4at%, which is mainlycontributed to the decrease of the plastic of Zr matrix composite decrease obviously.Zr matrix composite materials are prepared by adding SiC particles. It was found thattheir mechanical properties increase apparently. Through results of the XRD and SEMshowed: SiC,Zr,Ti produce for (ZrTi)(SiC)_0.7in synthetic reaction.(ZrTi)(SiC)_0.7,Zr and Ti happened eutectic reaction at the grain boundary. At the same time,becauseof the fast cooling speed and temperature gradient,(ZrTi)(SiC)_0.7formed lathingstructures. The dependence of the mechanical properties of Zr based alloy with SiCparticles on different cooling rate was investigated by tensile test. It was found thattensile strength and stretch rate of Zr base alloy with the content of SiC0.58wt%are1171MPa and4.56%by the liquid nitrogen quench treatmen. Its tensile strength is200MPa higher and stretch rate is3times than the same processing of Zr₅₀Ti₅₀alloyrespectively. Furthermore adverse ω phase is avoided to produce in Zr matrixcomposite.Zr matix composite materials with different content of Cr₃C₂particles areprepared. Through results of the XRD showed: Cr₃C₂and ZrTi alloy produced for ZrCin synthetic reaction. The Cr element is solution in ZrTi alloy. The α phase of matrix transformed to β phase when content of Cr₃C₂is higher than2.59wt%. The mechanicalproperties of Zr-based alloys with different content of Cr₃C₂were studied by tensiletest. the results show that: tensile strength and stretch rate of Zr base alloy with added0.86wt%Cr₃C₂are1026MPa and16%respectively.