Light bimetal composite drill rod and manufacturing process thereof

The invention discloses a light bimetal composite drill rod which comprises a drill rod male connector and a drill rod female connector and further comprises a bimetal composite rod body, and the two axial ends of the bimetal composite rod body are connected with the drill rod male connector and the drill rod female connector respectively. The bimetal composite rod body comprises a steel outer pipe and a light alloy inner pipe arranged in the steel outer pipe in a sleeved mode, and middle transition alloy is arranged between the steel outer pipe and the light alloy inner pipe. According to the light bimetal composite drill rod, the advantages of high strength and wear resistance of steel and the characteristics of high specific strength and corrosion resistance of light alloy are fully utilized, electrochemical corrosion is prevented by adopting a light alloy pipe body surface treatment process, the outer wall is coated with a thin-layer steel pipe, or a light alloy pipe structure is clamped between two layer