Influence of Flank Wear on the Microstructure Characteristics of the GH4169 Metamorphic Layer under High-Pressure Cooling

Abstract

Since the flank has an important influence on the surface of a workpiece, and as microstructure flaws of the surface metamorphic layer are a key factor that affects the service performance of a part, this work studied the influence of flank wear on the microstructure characteristics of the metamorphic layer under the conditions of high-pressure cooling. First, Third Wave AdvantEdge was used to create a simulation model of cutting GH4169 using tools with different flank wears under high-pressure cooling. The simulation findings emphasized the impact of flank wear width (VB) on the cutting force, cutting temperature, plastic strain, and strain rate. Second, an experimental platform was established for cutting GH4169 under high-pressure cooling, and the cutting force during the machining process was recorded in real time and compared with the simulation results. Finally, an optical microscope was used to observe the metallographic structure of the GH4169 workpiece section. The microstructure characteristics of the workpiece were analyzed using a scanning electron microscope (SEM) and electron backscattered diffraction (EBSD). It was discovered that, as the flank wear width increased, so did the cutting force, cutting temperature, plastic strain, strain rate, and plastic deformation depth. The relative error between the simulation results of the cutting force and the experimental results was within 15%. At the same time, near the surface of the workpiece, there was a metamorphic layer with fuzzy grain boundaries and refined grain. With an increase in flank wear width, the thickness of the metamorphic layer increased from 4.5 μm to 8.7 μm and the grain refinement intensified. The high strain rate promoted recrystallization, which caused an increase in the average grain boundary misorientation and high-angle grain boundaries, as well as a reduction in twin boundaries.

Optimizing Machining Efficiency in High-Speed Milling of Super Duplex Stainless Steel with SiAlON Ceramic Inserts

“…This phenomenon can be attributed to the reduction in tool clearance angle caused by flank wear, which in turn enlarges the contact area between the flank and the workpiece surface. Consequently, increased friction in the contact region leads to higher cutting forces [28]. This is even more important when considering the machining of the UNS S32750 alloy due to its low thermal conductivity and susceptibility to strain hardening.…”

Research on Cutting Layer Characteristics of Superalloy under High-Pressure Cooling

“…The results showed that high-pressure cooling can reduce the wear of the tool rake face caused by chip plastic side flow. Wei et al [29] found that by studying the influence of tool wear on the microstructure of the metamorphic layer under high-pressure cooling conditions, with the increase of flank wear width, the cutting force, cutting temperature, plastic strain, and strain rate showed a significant upward trend. Zhang et al [30] found through experimental research on cutting GH4169 under high-pressure cooling that the degree of influence of cutting amount and coolant pressure on tool vibration was in order of feed speed, cutting depth, cooling pressure, and cutting speed.…”