Machining Principles and Advantages of Honing Tubes via Extrusion Forming

Honing tubes are manufactured through extrusion forming. This process creates residual compressive stress on the surface, which helps seal microcracks on the surface and prevents the expansion of sedimentation. In turn, this enhances the surface corrosion resistance, slows down the formation or propagation of fatigue cracks, and thereby improves the fatigue strength of honing tubes.

Through extrusion forming, a cold work hardening layer is generated on the extruded surface. This reduces the plasticity and brittle fracture of the contact surface of the cutting pair, thereby enhancing the wear resistance of the honing tube’s inner wall. At the same time, it avoids burns caused by cutting. After extrusion, the reduction in surface roughness value can improve the fitting performance of the honing tube.

Extrusion forming is a non-cutting machining method. It utilizes the plastic deformation of metal materials at room temperature to flatten the micro-irregularities on the surface of honing tube workpieces, thereby achieving the goal of modifying the surface structure, mechanical properties, shape, and dimensions. Therefore, this method can simultaneously achieve two objectives—forming machining and performance enhancement—which cannot be accomplished by cutting processes alone.

No matter which machining method is used, the surface of the part will always have fibrous uneven tool marks, showing an overlapping undulating peak-valley pattern.

Principle of Extrusion Forming Machining: It is a pressure-forming machining process that utilizes the cold plastic deformation characteristics of metal materials at room temperature. A certain pressure is applied to the surface of the honing tube workpiece using extrusion tools, causing the metal material on the workpiece surface to undergo plastic deformation and flow. This metal fills the original residual concave valleys, thereby reducing the surface roughness value of the honing tube workpiece.

Due to the plastic deformation of the extruded surface metal, the surface structure undergoes cold hardening, the crystal grains are refined, forming dense fibers, and a stress layer is created. This increases the hardness and tensile strength, thereby improving the wear resistance, corrosion resistance, and fitting performance of the honing tube workpiece surface. Extrusion forming is a non-cutting plastic deformation machining method.