The invention is suitable for the technical field of wood non-
adhesive connection, and provides a China fir round tenon segmented variable-speed rotary
friction welding method which is characterized in that aiming at the characteristics of China fir materials, a'preheating-main
welding-stable
welding 'three-stage variable-speed process is innovated, and a special tenon with a spiral guide groove and an annular stop boss is matched, so that the China fir round tenon segmented variable-speed rotary
friction welding is realized. And the surface is coated with a
lignin-
nano silicon dioxide composite modifier. The method comprises the steps of mortise precision pretreatment, tenon modification preparation, segmented
welding and heat preservation curing, specifically, gradient heating is conducted to 180-220 DEG C in the preheating stage,
lignin is melted at a high speed in the main welding stage, and three-dimensional mechanical
interlocking is formed at a
low speed in the stable welding stage. The problems of high wood
loss rate, insufficient joint strength and poor
water resistance in the prior art are solved, compared with the prior art, the pulling resistance of the welded joint is greatly improved, the wood
loss rate is remarkably reduced, the thickness swelling rate of water absorption in 24 hours is greatly reduced, the process is stable, the
automation degree is high, and
adhesive pollution is avoided; and the industrial
green production requirements of
furniture manufacturing and wood structure buildings are met.