Efficient Use of Coolant in Narrow Kerfs During the Sawing of Titanium Alloys via Simulation of Thermal and Mechanical Fluid-Solid Interactions (Effi-Ti-Sim)

The Effi-Ti-Sim project is a subproject of Priority Program 2231 FluSimPro – Efficient Cooling, Lubrication, and Transport – Coupled mechanical and fluid-dynamic simulation methods for the realization of efficient production processes.

Objectives and Innovation Potential

The overarching goal of this research project is to significantly improve efficiency in the use of coolant during circular saw machining of titanium alloys. The focus is on optimizing coolant volume, pressure, and energy consumption.
This is based on an improved understanding of the thermal and mechanical fluid-solid interactions. By transitioning from conventional flood lubrication to a targeted internal KSS supply or minimum quantity lubrication (MQL), significant savings in energy, resources, and costs can be achieved.

Scientific Approach and Methodology

Multiscale coupled models are used to represent these complex processes. These models simulate thermodynamic, fluid mechanical, and machining effects during chip formation and chip transport. The modeling includes:
•    Tribology and force interactions: Analysis of mechanical stresses in the cutting gap.
•    Heat transfer and cooling effects: Investigation of detailed mechanisms, taking evaporation effects into account.
•    Fluid mechanics: Simulation of transient and turbulent flow conditions as well as particle flow (chips).

The realism of the simulations is ensured by taking into account specific chip formation mechanisms and the special conditions in narrow cutting gaps.

Project Structure and Schedule

Phase 1: Modeling and Validation The focus is on researching fundamental modeling approaches and defining the necessary interfaces for their integration. The methodological implementation relies on a combination of experimental analyses conducted as part of fundamental and analog experiments, as well as targeted process tests for circular saw machining. The goal is to create a validated database for subsequent simulation steps.

Phase 2: Comprehensive Multiphysics Simulation: Based on the previously identified and efficiently designed coupling options, a comprehensive, interdisciplinary simulation is implemented. In this phase, the complex mechanisms of action are integrated into a multiphysics model to realistically simulate the entire machining process.

Phase 3: Simulation-Based Optimization of IKZ Circular Sawing Phase 3 optimizes the circular sawing of titanium alloys through the highly efficient use of coolant via IKZ. Tool design (chip clearance, number/position of IKZ holes) and process parameters (tooth feed, cutting speed, coolant pressure/flow rate) are optimized for minimal coolant flow. Advanced models predict flow as well as thermal and mechanical effects and derive an optimal internal coolant supply. The study examines whether the geometry can supply trailing teeth without an internal coolant supply to reduce the number of holes and manufacturing costs; to this end, coupled simulation approaches are being expanded.

Technical implementation

Upon completion of the funding period, a validated and expanded simulation environment is now available that reliably predicts flow processes as well as thermal and mechanical interactions during circular sawing with internal coolant supply (ICS) and evaluates design variants. Building on this, design guidelines for circular saw blades made of titanium alloys were developed, including optimized chip space geometries as well as the number and position of the ICF holes. Additionally, derived process guidelines define parameter windows for tooth feed, cutting speed, coolant pressure, and flow rate to minimize the required flow rate while maintaining a stable process. It has been demonstrated that a specific tool and hole geometry creates flow conditions in the cutting gap that reliably supply coolant to trailing teeth without IKZ. This allows for a significant reduction in the number of IKZ holes required and manufacturing costs while maintaining consistent process quality. The coupled modeling and simulation approach has been validated and forms the basis for future designs and applications.