Synthesis and oxygen evolution mechanism of hypoxia carbon-control titanium-zirconium-molybdenum alloy

Due to alloying elements' influence, it is difficult for TZM alloys to simultaneously control the carbon content and oxygen content during the hydrogen sintering. In this paper, the preparation process of TZM alloy is studied, the carbon content and oxygen content of the preparation process are detected, and the control mechanism of the carbon and oxygen content is clarified. The carbon and oxygen content of TZM alloy is controlled at 30 ppm and 70 ppm, respectively. The existence form of oxygen and the evolution mechanism of oxygen during the preparation of TZM alloy were studied. The results show that when the oxygen content of the TZM alloy is about 2000 ppm, there are many secondary phases located in the grain boundary, and its main component is TiO₂ (containing a small amount of ZrO₂). With the oxygen content of the TZM alloy decreases, the number of secondary phases decreases, the size becomes smaller, and the Zr content in the composition gradually increases. When the oxygen content of TZM alloy is 70 ppm, there is no apparent secondary phase in the alloy, the main chemical composition of the secondary phase is ZrO₂, and fracture mode of the alloy changes from intergranular fracture to intergranular and transgranular mixed fracture. As the oxygen content of TZM alloy decreases, the titanium and zirconium elements can be better solubilized in the molybdenum matrix. The alloy's primary strengthening mode gradually changes from the secondary phases strengthening to the solid solution strengthening.