Mechanisms and FEM Simulation of Chip Formation in Orthogonal Cutting In-Situ TiB2/7050Al MMC

Abstract

The in-situ TiB2/7050Al composite is a new kind of Al-based metal matrix composite (MMC) with super properties, such as low density, improved strength, and wear resistance. This paper, for a deep insight into its cutting performance, involves a study of the chip formation process and finite element simulation during orthogonal cutting in-situ TiB2/7050Al MMC. With chips, material properties, cutting forces, and tool geometry parameters, the Johnson–Cook (J–C) constitutive equation of in-situ TiB2/7050Al composite was established. Then, the cutting simulation model was established by applying the Abaqus–Explicit method, and the serrated chip, shear plane, strain rate, and temperature were analyzed. The experimental and simulation results showed that the obtained material’s constitutive equation was of high reliability, and the saw-tooth chips occurred commonly under either low or high cutting speed and small or large feed rate. From result analysis, it was found that the mechanisms of chip formation included plastic deformation, adiabatic shear, shearing slip, and crack extension. In addition, it was found that the existence of small, hard particles reduced the ductility of the MMC and resulted in segmental chips.

Thermo–Mechanical Behavior and Constitutive Modeling of In Situ TiB2/7050 Al Metal Matrix Composites Over Wide Temperature and Strain Rate Ranges

“…The in-situ TiB 2 (6 wt%) particle-reinforced 7050 aluminum matrix composites (shortened as TiB 2 /7050 Al composites) used in this study are the same as those in a previous work [29]. The material was fabricated via the controllable salt-metal reaction technique of K 2 TiF 6 and KBF 4 by the State Key Laboratory of Metal Matrix Composites of China [3,30].…”

“…In our previous study [29], the JC constitutive model of TiB 2 /7050 Al composites is calculated from the basic mechanics of orthogonal cutting and finite element simulation based on reference [25]. A set of orthogonal cutting experiments were conducted by a CNC lathe.…”

“…After each test, the cutting chips were collected and further analyzed for the shear stress, strain, strain rate and temperature in the shear zone. A more detailed description of orthogonal cutting experiment with cutting parameter ranges can be found in the reference [29]. The basic schematic diagram of orthogonal cutting experiment is shown in Figure 6.…”

“…The other is to study the descriptive ability of JC and KL models concerning TiB 2 /7050 Al composites. In addition, the result of the JC model obtained by an orthogonal cutting experiment from our previous research [29] is compared. The established constitutive model can be well used for the simulation study of TiB 2 /7050 Al composites under different processing technologies.…”

Tailored Chip Breaker Development for Polycrystalline Diamond Inserts: FEM-Based Design and Validation

“…This makes it critical to control the chip evacuation process, which can be satisfactorily achieved using proper chip breaker geometry to bend the generated chip sufficiently so that it breaks on its own. Researchers have studied different methodologies to optimize chip breakers design, experimentally [16] and combining experimentation and simulation [14,31], but most of them restricted their work to non-PCD insert tools. On the other hand, the authors previously worked on developing chip breakers for PCD inserts welded into milling-tools [14].…”