| Titanium matrix composites (TMCs) were widely used in aerospace field due to their high specific strength, specific modulus and high-temperature properties. However, there was a big gap in both amount and application level between home and abroad. The reason was the lack of machine technology. So, it is necessary that we should improve our workability of titanium matrix composites to meet the demands of aerospace development.Thermohydrogen processing offered an effective method for improving the hot working of titanium matrix composites. This so-called thermohydrogen processing (THP) is based on the modifying effect of hydrogen as an alloying element on phase, and kinetics of phase transformations in titanium alloys. The addition of some hydrogen increases the ductility and reduces the flow stress of theα, pseudo-α,α+βand intermetallic-base alloys at usual temperature of hot working. Use of hydrogen as a temporary alloying element in titanium alloys is an attractive approach for enhancing processability and also for controlling the microstructure and thereby improving final mechanical properties.In this paper, Ti-8Al-1Mo-1V matrix composites reinforced with different volume percentage reinforcements (TiB and TiC) were synthesized firstly by a consumable arc-melting technology utilizing the reaction between Ti and C, B4C. The phase constituents were identified by XRD while microstructure characterization was observed by optical microscopy (OM) and scanning electron microscope (SEM). The effects of reinforcements on the microstructures, tensile properties and fractures at room temperature were discussed; then, the samples of composites and Ti-8Al-1Mo-1V alloy were hydriding at 750℃. After charging, we also use XRD, OM, SEM, etc. to observe constituents and microstructure characterization of the composites and matrix alloy. SHMADZU AG-150 was used to test its mechanical property at high temperature. The main results of this paper can be described as follows:1. Ti-8Al-1Mo-1V matrix composites reinforced with different volume percentage of reinforcements (TiB and TiC) was successfully in situ synthesized utilizing the reaction between Ti and C, B4C though homogeneously melting in a consumable vacuum arc-remelting furnace. The elastic moduli values of composites were 17.6% and 38.4% increases respectively in comparison with that of Ti-8Al-1Mo-1V matrix. The highest elastic moduli value was above 160Gpa.2. Through high temperature mechanical test we can find that: at 750℃, the flow stress decreased, reached a minimum, and then increased when the hydrogen concentration increased. The elongation of matrix alloy increased first, after reached maximum and then decreased when deforming at 880℃, while the elongation of composites increased when the hydrogen concentration increased.3. After charging, first, theαphase of (TiB+TiC)/ Ti-8Al-1Mo-1V composites and matrix alloy decreased andβphase increased which indicated that hydrogen decreased the temperature of theαtoβphase transformation. With the increasing of hydrogen concentration, a hydride was observed which indicated that reactionβ→α+TiH2 occurred. The hydride resulted in a redistribution of alloying elements between the phases and refined the structure of the materials.4. From the true strain-tress curve we can find that the addition of hydrogen could greatly decrease the resistance of deformation.
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