Abstract:GH4169 alloy samples with different TC4 contents were prepared using ball milling alloying and laser melting deposition by adding TC4 alloy powder to conventional GH4169 alloy powder instead of Al and Ti alloying. The effects of TC4 addition on microstructure and properties of GH4169 alloy prepared by laser melting deposition were investigated. The results show that TC4/GH4169 alloy is mainly composed of coarse columnar crystals, but the primary dendrite arm distance and grain size of the columnar crystals decrease. Besides, the Laves phase changes from continuous long chain to diffused short rod with the aspect ratio decreased from 9.2 to 2.6. During the deposition process, TC4 is melted, of which Ti and Al elements are released, then fully dissolved into GH4169 alloy melt, and finally participated in solidification and microstructure formation of the alloy. The addition of TC4 increases the solidification rate of the alloy deposition pool and reduces the segregation of elements in the solidification structure. Besides, the addition of TC4 promotes precipitation of γ? and γ? in the solidification microstructure. Thus, the hardness and mechanical properties of the deposited alloy are improved. The addition of TC4 shows effects of fine crystal strengthening, solid solution strengthening, and precipitation strengthening.