Microstructure and Properties of Soluble Alloy Used for Fracturing Separation Tools

The Mg-Ca-Zn-Fe-Ni-Cu soluble alloy were developed and prepared. The microstructure and mechanical properties of the cast and hot-extruded alloy were compared, and the dissolving property and application performance of the hot-extruded alloy were investigated. The results indicate that the test alloy with density of 1.8 g·cm^-3 was composed of α-Mg,Mg₂Ca,Mg₂Ni,Mg₂Cu and Mg₆Ca₂Zn₃ phases. The matrix phase and precipitated phase of hot-extruded alloy distributed along the extrusion direction and exhibited a smaller size than the cast alloys. The tensile strength, elongation and hardness of alloy were increased after hot-extruding. The soluble rate of hot-extruded alloy increased when temperature rose. The hot-extruded alloy showed a mass loss of 40% after dissolved for 24 h at room temperature while dissolved completely after 24 h at 60℃. The pressure drop rate of frac-ball fabricated by hot-extruded alloy was 0.86% under 70 MPa at 90℃, which showed a good leakproofness. Field test results showed that the frac-ball had an excellent application performance.