Influence Of Alloying Elements On Microstructure And Properties Of Laser Clad Ti-Fe Alloy Coatings

In recent years Ti-Fe binary eutectic alloy system is a new titanium alloy system. Ti-Fe alloy not only has titanium alloy’s excellent performance(low density、high specific strength and excellent heat resistance), but also has excellent mobility, physical and chemical compatibility. It is an ideal material of surface modification of titanium alloy. So, Ti-Fe alloy coatings with different content of Nb4Si and Zr are prepared by laser cladding on the surface of TA15that has important value of engineering application, respectively. The influence of Nb4Si and Zr content on microstructures and properties of the coatings are investigated.The experimental results show that when Nb4Si additions are added from0.5at.%to4at.%, the Ti-Fe alloy coatings are mainly composed of β-Ti dendrites and eutectic structure (β-Ti+TiFe). Alloy coating elastic modulus is first decreased and then increased with Nb4Si content change. And we begin to find Nb5Si3phase. When Nb4Si additions are added to2at.%, alloy coating hardness and wear resistance are the best. Alloy coating elastic modulus is first decreased and then increased with Nb4Si content change. When Nb4Si additions are added to2at.%,its resistance to stress and strain ability are the best.The Ti-Fe alloy coatings are mainly composed of β dendrites, eutectic structure (β-(TiZr)+TiFe+Zr2Fe) and Zr3Fe.Ti-Fe alloy coatings with different Zr additions, its dendrites organization is decreased first and then increased with the increase of Zr content. Its eutectic structure is also first increased and then decreased. When Zr additions are added to7.1at.%, the organization achieve Ti-Fe-Zr eutectic point. The cladding layer of tissue is extremely small eutectic structure. It has high hardness, superior wear resistance and the organization is also very dense. When Zr addition amount exceeds the eutectic composition, its organization changed into coarse dendrites (β-Zr). Its hardness drops, and wear resistance is poor. In order to improve the performance of Ti-Fe alloy, Zr addition amount shouldn’t exceed the eutectic composition.