Experimental evaluation of an eco-friendly grinding process combining minimum quantity lubrication and graphene-enhanced plant-oil-based cutting fluid

Brittle-to-ductile transition in elliptical vibration-assisted diamond cutting of reaction-bonded silicon carbide

Weak mechanical properties affect the application of PEEK as an implant. Carbon fiber (CFR) reinforcement provides an excellent solution to improve the mechanical strength of PEEK and to provide perfect matching of elastic modulus between CFR-PEEK composites and human bone. To investigate the effect of carbon fiber content on the mechanical, thermal properties and cytotoxicity of CFR reinforced PEEK composites, a series of CFR-PEEK composites with different carbon fiber content (25 wt%, 30 wt%, 35 wt%, 40 wt%) was prepared in this work. Thermal decomposition behavior and melting temperature were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. Subsequently, mechanical properties including bending strength, compressive strength, impact strength and hardness were tested respectively. Afterwards, the fracture morphology of the bending test samples was observed by scanning electron microscopy (SEM). In addition, murine fibroblast L929 cells were adopted for cytotoxicity test by CCK-8 assay in vitro, and the morphology of cells was observed by inverted fluorescence microscope simultaneously, cell compatibility of CFR-PEEK composites was tested.

Mechanical properties and cytotoxicity of hierarchical carbon fiber-reinforced poly (ether-ether-ketone) composites used as implant materials

Effects of laser-assisted grinding on surface integrity of zirconia ceramic

Comparison of Properties of Carbon Fiber Reinforced Thermoplastic and Thermosetting Composites for Aerospace Applications

The aim of this paper is to compare the mechanical property and machinability of Polyetheretherketone (PEEK) and 30 wt% carbon-fibers reinforced Polyetheretherketone (PEEK CF 30). The method of nano-indentation is used to investigate the microscopic mechanical property. The evolution of load with displacement, Young's modulus curves and hardness curves are analyzed. The results illustrate that the load-displacement curves of PEEK present better uniformity, and the variation of Young's modulus and hardness of PEEK both change smaller at the experimental depth. The machinability between PEEK and PEEK CF 30 are also compared by the method of single-point diamond turning (SPDT), and the peak-to-valley value (PV) and surface roughness (Ra) are obtained to evaluate machinability of the materials after machining. The machining results show that PEEK has smaller PV and Ra, which means PEEK has superior machinability.

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Comparison and Analysis on Mechanical Property and Machinability about Polyetheretherketone and Carbon-Fibers Reinforced Polyetheretherketone

The application of silicon carbide (SiC) is often limited due to its low machining efficiency and unpredictability about the results of the grinding process. The aim of this paper is to set up finite element analysis models (FEM) about microgrinding process of SiC, to study the change processes about tangential and normal grinding force which can lead to stress and strain inside SiC material under different grinding parameters, and to predict the results before the grinding process. Adaptive remeshing technique is used to minimize the computational time without sacrificing the accuracy of the results in the simulation of SiC grinding process. The research results can be used to choose reasonable grinding parameters based on the required surface quality.

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Finite element analysis and simulation about microgrinding of SiC

Compound sinusoidal grid surface with nanometric finish plays a significant role in modern systems and precision calibrator, which can make the systems smaller, the system structure more simple, reduce the cost, and promote the performance of the systems, but it is difficult to design and fabricate by traditional methods. In this paper, a compound freeform surface constructed by a paraboloidal base surface and sinusoidal grid feature surface is designed and machined by slow tool servo (STS) assisted with single point diamond turning (SPDT). A novel combination of the constant angle and constant arc-length method is presented to optimize the cutting tool path. The machining error prediction model is analyzed for fabricating the compound sinusoidal grid surface. A compound sinusoidal grid surface with 0.03 mm amplitude and period of 4 is designed and cutting process is simulated by use of MATLAB software, machining experiment is done on ultra-precision machine tool, the surface profile and topography are measured by Taylor Hobson and Keyence VR-3200, respectively. After dealing with the measurement data of compound freeform surface, form accuracy 4.25 μm in Peak Village value (PV), and surface roughness 89 nm in Ra are obtained for the machined surface. From the theoretical analysis and experimental results, it can be seen that the proposed method is a reasonable choice for fabricating the compound sinusoidal grid surface.

Ultra-Precision Machining of a Compound Sinusoidal Grid Surface Based on Slow Tool Servo

The utility model relates to an interior jump ring automatic installation machine belongs to the machine-building field. Installing crossbeam stand, platform, work piece positioner on the base, installing jump ring pusher, feed cylinder positioning clamping device on this platform, install the crossbeam lead screw device of realizing along the motion of Y direction on the crossbeam stand, on stand lead screw device was fixed in the slider of crossbeam lead screw device, six prismatic grain-clamping tables were connected with stand lead screw device. The advantage is novel structure, has feed cylinder positioning clamping device to have a packing force in advance to the jump ring in the jump ring feed cylinder, through the cooperation with jump ring pusher can be fine the propelling movement of realization jump ring, simple automatic the installation can be realized through the cooperation of jump ring pincers and bloated cover device with the installation to centre gripping at the jump ring, and carried out the location centre gripping to the work piece to can realize having improved the commonality to the centre gripping of different work pieces through changing the tight arm of work piece clamp.

Interior jump ring automatic installation machine

The invention relates to an automatic installation machine of an internal clamp spring and belongs to the field of machine manufacturing. A cross beam stand column, a platform and a workpiece locating device are installed on a base, a clamp spring pushing device and a material barrel locating and clamping device are installed on the platform, a cross beam lead screw device for achieving movement in the Y direction is installed on the cross beam stand column, a stand column lead screw device is fixed to a sliding block of the cross beam lead screw device, and a hexagonal prism clamping table is connected with the stand column lead screw device. The automatic installation machine of the internal clamp spring has the advantages that the material barrel locating and clamping device is arranged and has pre-tightening pressure on the clamp spring in a clamp spring barrel, and the clamp spring can be well pushed through cooperation of the material barrel locating and clamping device and the clamp spring pushing device; simple automated installation can be achieved through cooperation of a pair of clamp spring pincers and an sleeve expanding device when the clamp spring is clamped and installed; in addition, a workpiece is located and clamped, and different workpieces can be clamped by replacing workpiece clamping arms, so generality is improved.

Sun Changrui

Papers

Comparison and Analysis on Mechanical Property and Machinability about Polyetheretherketone and Carbon-Fibers Reinforced Polyetheretherketone

Finite element analysis and simulation about microgrinding of SiC

Ultra-Precision Machining of a Compound Sinusoidal Grid Surface Based on Slow Tool Servo

Interior jump ring automatic installation machine

Automatic installation machine of internal clamp spring