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Elliptical vibration assisted cutting (EVAC) is gradually being one of the most potential machining methods for difficult to machine materials. However, the elliptical trajectory causes periodic residual traces on machined surface. A novel quasi-intermittent vibration assisted swing cutting (QVASC) device driven by two piezoelectric actuators is proposed to reduce the residual traces between adjacent paths and improve surface quality. An X-shaped flexure hinge was used to suppress the mutual interference between two driving shafts and realize kinematic decoupling. The mechanical configuration and geometric parameters of the proposed device were designed based on the analyzing of kinematics, dynamics, and flexible characteristics. The effectiveness of the proposed device was verified by finite element analysis and off-line performance test. Tests results show that the maximum coupling ratio of motion axis, maximum motion stroke, and minimum resolution of QVASC device are 1.65%, 19.943 μm, and 9.55 nm, which are satisfied with the design and machining requirements. Finally, systematic turning experiments were carried out to verify the effectiveness of the proposed device in restraining cutting residual traces. The experimental results indicate that the proposed device can effectively inhibit the generation of periodic residual traces, which validates the feasibility of the QVASC device. [ABSTRACT FROM AUTHOR]

Glass‐ceramics with high performance and high crystallinity was produced using rare earth blast furnace slag (REBFS) as the primary raw material, along with composite nucleating agents Fe2O3 and Cr2O3. The migration pattern, distribution characteristics, and solidification properties of heavy metals in glass‐ceramics were investigated by the controlled heat treatment. The findings indicated that the heat treatment temperature has a significant effect on the distribution and color of heavy metals in glass‐ceramic. In the crystallized glass‐ceramic, spinel acts as the crystal core for heavy metal solidification, Cr, Cu, and Mn can exist stably in the spinel by the solid solution. The glass‐ceramic was expected to be used as a decorative building material. [ABSTRACT FROM AUTHOR]

Three-dimensional elliptical vibration assisted cutting (3D-EVC) technology has been widely used in many high-precision technical fields due to its high-efficiency processing characteristics. However, the hysteresis and nonlinearity caused by the piezoelectric drive in the 3D-EVC system will impact the system control accuracy. This paper mainly studies the hysteresis and nonlinearity of the system, the feedforward-gray predicted fuzzy PID compound controller based on the generalized Bouc-Wen hysteresis nonlinear model and it is designed to realize the hysteresis compensation of the system. In this paper, input voltage and output displacement are represented by a mathematical relationship, and this relationship of the 3D-EVC system will be described by the generalized Bouc-Wen model. The improved flower pollination algorithm (IFPASO) is adopted in the identification process of parameters. A compound control strategy is formed based on traditional feed-forward control combined with fuzzy PID feedback control to compensate for hysteresis and nonlinearity, and an improved gray prediction model is introduced into the feedback loop. The 3D-EVC system tracking experiment verifies the effectiveness of the designed compound controller. Experiments have proved that the hysteresis component of the system is significantly reduced after the use of the compound controller for hysteresis compensation, and the system has a higher degree of stability. [ABSTRACT FROM AUTHOR]

In order to deeply understand the cutting mechanism of SiCp / Al in ultrasonic vibration-assisted turning, a prediction model of a cutting temperature field of SiCp / Al composites in UVAC (ultrasonic vibration-assisted cutting) was established. A theoretical model of instantaneous cutting depth and transient shear angle was established considering the real-time changing cutting depth, tool front angle and shear angle characteristics of UVAC. The relationship between cutting speed, shear speed and chip flow speed in UVAC processes is revealed, as well as the shear force and the front cutter friction force. Finally, the influence of heat generated by the heat source zone and shear heat source zone on the temperature rise was calculated, and the temperature field model was established. The experiment of processing SiCp / Al composites by UVAC was carried out. SiCp / Al composites with 25 % volume fraction were turned, and the cutting temperature data were measured and recorded by an infrared thermal imaging device. The cutting speed, cutting depth and feed rate were tested by a single factor, and the changes in cutting temperature under different parameters were compared. Finally, the experimental data were compared with the theoretical values to verify the validity of the theoretical model. [ABSTRACT FROM AUTHOR]

Compared to conventional polishing methods, magnetorheological polishing has no subsurface damage and a has good polishing effect, which is suitable for fused silica glass surface processing. However, the existing magnetorheological polishing material removal model has low processing efficiency and uneven removal, which cannot realize the deterministic processing of parts. The material removal (MR) model of fused silica glass is established by convolving the dwell time with the material removal function. The residence time is Fourier transformed. The consequence of process variable such as machining time, workpiece rotational frequency, machining gap and X-direction deflection on the MR of workpiece interface are analyzed. Experiments verify the validity of the material removal model. The surface precision PV value of the workpiece surface under the optimal process parameters was decreased from 7.959 nm to 0.609 nm for machining. The experiment results indicate that the established MR model can be implemented as the deterministic MR of the optical surface and ameliorate the surface accuracy of the workpiece surface. [ABSTRACT FROM AUTHOR]