Mechanical micromachining is a very flexible and widely exploited process, but its knowledge should still be improved since several incompletely explained phenomena affect the microscale chip removal. Several models have been developed to describe the machining process, but only some of them consider a rounded edge tool, which is a typical condition in micromachining. Among these models, the Waldorf's slip-line field model for the macroscale allows to separately evaluate shearing and ploughing force components in orthogonal cutting conditions; therefore, it is suitable to predict cutting forces when a large ploughing action occurs, as in micromachining. This study aims at demonstrating how this model is suitable also for micromachining conditions. To achieve this goal, a clear and repeatable procedure has been developed for objectively validating its force prediction performance at low uncut chip thickness (less than 50 μm) and relatively higher cutting edge radius. The proposed procedure makes the model generally applicable after a suitable and non-extensive calibration campaign. This article shows how calibration experiments can be selected among the available cutting trial database based on the model force prediction capability. Final validation experiments have been used to show how the model is robust to a cutting speed variation even if the cutting speed is not among the model quantities. A suitable set-up, especially designed for microturning conditions, has been used to measure forces and chip thickness. Tests have been performed on 6082-T6 Aluminum alloy with different cutting speeds and different ratios between uncut chip thickness and cutting edge radius.

As the complexity of micro-products increases, the micro-manufacturing processes, tool setups, and measurement processes have to be more precise and efficient. Combining them in a multi-stage process chain can effectively improve production accuracy and performance and reduce limitations and production costs. This paper focuses on the process chains for the manufacturing of micro-products and presents the state of the art, highlighting the specific characteristics of the existing models of process chains for micro-manufacturing. Based on the critical review of these characteristics, an evolution of the process chain model for micro-manufacturing is proposed, considering machining, measurement/characterization, referencing processes, and their combination into a suitable sequence. The proposed model accounts for relevant aspects of micro-manufacturing, such as size effects and technological fingerprints at the microscale. This paper also discusses the hierarchical properties of multiple micro-manufacturing process chains and some specific techniques to address the critical issue of referencing processes. Furthermore, some relevant case studies involving micro-electrical discharge machining, micro-injection molding, additive manufacturing, and micro-milling are presented to demonstrate how the micro-manufacturing potentiality can be increased using process chains.