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The increase in convenience and value of many industrial and household products due to their size and weight reduction over the years has triggered the rapid development of micromachining technologies. V-grooves have gained attention in micromachining due to their versatile use on a wide variety of products. To date, a double-flank axial cutting strategy involving a constant cutting depth set is commonly used in the fabrication of V-grooves. By contrast, the current study introduces a single-flank cutting strategy (SFCS) with two main implementations: constant chip thickness (CCT) and constant cutting area (CCA). The two implementations of the proposed SFCS were compared in terms of both experimental and numerical force results. The thorough comparison performed revealed advantages and disadvantages for both implementations in terms of cutting force magnitude, machining time, and surface quality obtained after a finishing pass. The results obtained revealed that a strong linear dependence exists between the area of material removed and the cutting force in the CCT implementation, whereas the CCA implementation is characterized by a quasi-constant cutting force magnitude owed to the constant area of material removed in each cutting pass. Moreover, while both implementations yielded surface quality within the optical surface quality range (Sa under 15 nm), the CCT variant is characterized by longer machining times and lower force levels, whereas the CCA implementation employs fully controllable cutting forces at preset levels. As such, the CCA implementation can be associated with stable cutting dynamics, predictable tool wear, and unanticipated tool breakage. [ABSTRACT FROM AUTHOR]

Temperature gradients across tooling surfaces and within parts during the compression molding process represent a major contributor to warpage patterns. The main objective of the current study was to analyze the limitations of thermography as a method to be used for the measurement of part surface temperature. Comparisons performed against simulation and thermocouple data revealed that while thermography is a relatively accurate method, reflectivity and environmental radiation could cause errors of up to 8%. Nonetheless, since thermography data remains precise with respect to the relative temperature distribution, it was used for the assessment of the effect of compression molding process parameters on part ejection temperatures. In this regard, it was found that mold temperature has an overwhelming influence on final part temperature, whereas hold time has a less significant, but still measurable influence. Other parameters such as pressure, charge temperature, and charge orientation exhibited no practical significance. It was also found that parts exhibited strong temperature nonuniformities and gradients of nearly 25 °C within patterns that were largely consistent among parts. Given that this study also suggested that simulation yields reasonable temperature field predictions in compression molding, these results are expected to guide future warpage reduction efforts with possible effects on a wider adoption of composite components in automotive industry. [ABSTRACT FROM AUTHOR]

In five-axis machining of sculptured surfaces, the cutting tool is unable to continuously trace the intended curved tool path due to limitations of existing controllers for the commercial machine tools. Current industrial practice is thus to discretize the continuous tool path into a finite number of cutter contact (CC) points. An improved method of tool path discretization for five-axis sculptured surface machining is presented in this paper. While the tool posture along a tool path is tuned to ensure maximized material removal rate and to avoid gouging to the machined surface, the forward step lengths, characterized by the consecutive discretized CC points, are determined by maintaining the machined surface error within the specified tolerance. The conventional method employs chordal deviations to estimate the machined surface errors of the interpolated tool movements between consecutive CC points, which have been referred to as the geometry-based errors. It has been found that chordal deviations are not reliable estimations of the geometry-based errors. As such, the geometry-based errors are accurately evaluated in this work and the related algorithms are implemented to the machining of a typical Bezier surface patch. The results showed a reduction of about 30% in the number of discretized tool path segments compared with those of the conventional method. [ABSTRACT FROM AUTHOR]