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The Ti₂AlNb alloy and the titanium matrix composites can be joined by direct solid phase diffusion, but the high diffusion temperature causes the base metal to undergo a phase transition, even the joint properties were therefore deteriorated. A method for optimizing the properties of solid phase diffusion joints of Ti₂AlNb alloy and Ti matrix composites was proposed by using Ti foil intermediate layer. The results show that after adding 30 <i>μ</i>m Ti foil intermediate layer, the diffusion bonding temperature reduces from 950 ℃ to 850 ℃, the deformation rate reduces from 5% to 1.7%, and the decreasing of diffusion bonding temperature can effectively change the structure of the joint interface. The typical interface is Ti₂AlNb/B2 phase/α+β dual phase structure/Ti matrix composite, in which the strength of the joint increases by the formation of α+β dual phase structure at the joint interface.When the optimum diffusion bonding parameter is 850 ℃/60 min/5 MPa, the shear strength reaches a maximum value of 399 MPa. The diffusion bonding of Ti₂AlNb and Ti based composite at low temperature is realized.