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Compressive strength anisotropy of foliated rocks
Published in Hans Peter Rossmanith, Mechanics of Jointed and Faulted Rock, 2020
From the block samples of each rock type, at least fifteen core specimens were extracted at each of the three orientations on a small 2-speed diamond drill assembly using 36mm, 37mm, and 38mm internal diameter diamond core bits. Water was employed for cooling and flushing. A relatively uniform rate of drilling was essential for obtaining good quality cores. Also a great deal of care was exercised in removing the core from the barrel so as to reduce the risk of breakage along foliation. All the retrieved cores were trimmed on a small diamond saw and their ends ground flat and parallel to within tolerances specified in the Suggested Methods of the ISRM (International Society for Rock Mechanics, Anon. 1981) using a surface grinder with a diamond grinding wheel and a magnetic chuck mounted core-vise. Finally, core specimen dimensions were measured with a vernier caliper to the nearest 0.1mm after the core specimen was labelled.
Application of ultrasonic vibration assisted MQL in grinding of Ti–6Al–4V
Published in Materials and Manufacturing Processes, 2018
Rajeshkumar Madarkar, Sahaj Agarwal, Pirsab Attar, S. Ghosh, P. V. Rao
The grinding experiments were performed on CNC surface grinder (make: Chevalier) by a silicon carbide grinding wheel. The grinding wheel (dimension: 350 × 50 × 127 mm, specification: GC60K5V) and Ti–6Al–4V workpiece of 60 mm (length) × 60 mm (height) × 10 mm (width) were used in the experiments. The dressing of grinding wheel was done before every experiment for maintaining uniformity in all tests. Dynamometer (make: KISTLER) was used to measure the grinding forces. The grinding chips have been collected on carbon tape. After grinding operation, small pieces were cut from the ground surfaces using wire EDM machine. Further, SEM characterization of these cut ground surfaces and the grinding debris was done. Talysurf surface profilometer (make: Taylor Hobson) was used for measuring the ground surface roughness. The grinding experimental parameters described in Table 1 were suitably chosen based on the preliminary experimentations.
A study on the effect of polishing fluid volume in ball end magnetorheological finishing process
Published in Materials and Manufacturing Processes, 2018
Zafar Alam, Dilshad Ahmad Khan, Sunil Jha
Here, an experimental-based study is done to determine the optimum volume of the MRP fluid required for finishing. The effect of MRP fluid volume on the finished spot quality and size is studied. The experiments are performed on mild steel workpieces of 80 × 60 × 5 mm size and is held by a precision vice mounted on X-Y linear slide of a three-axis CNC BEMRF machine. Four ampere direct current is used to energize the multi-turn electromagnet coil through a DC power supply system. The tool spindle is given a rotational speed of 200 rpm maintaining a working gap of 1 mm. The selected parametric condition for experimentation is shown in Table 3. The above set of six experiments with varying fluid volume are conducted on three separate mild steel workpieces that are initially ground using a surface grinder machine. The experiments had good repeatability with almost all three workpieces showing similar results as discussed below. The size of finishing spot obtained with varying fluid volume for all three workpiece is shown in Fig. 6. The variation in terms of percentage difference between the highest and lowest diameter obtained on these three samples with each fluid volume sample is given as
Process parameter optimization and experimental evaluation for nanofluid MQL in grinding Ti-6Al-4V based on grey relational analysis
Published in Materials and Manufacturing Processes, 2018
Guotao Liu, Changhe Li, Yanbin Zhang, Min Yang, Dongzhou Jia, Xianpeng Zhang, Shuming Guo, Runze Li, Han Zhai
Precision surface grinder (Model: K-P36) and silicon carbide-vitrified bond grinding wheel (grain size: 80 mesh. Model: GC80K12V) were used in the experiment. Lubricants were transported to the grinding area through the MQL supply system (Model: KS-2106). For each experiment, the normal, tangential, and axial grinding forces were measured by a grinding force dynamometer (Model: YDM-III99). A thermocouple (Model: MX100) was used to measure the temperature of grinding area. Before recording the grinding force and temperature, the workpiece was preground. After a relatively stable grinding force and temperature can be got, we started to record 30 grinding passes, and all valid data were got from the average of 30 measurements. After grinding operation, the workpiece surface and grinding debris were analyzed by using SEM (Scanning electron microscope, model: S-3400N). Each workpiece’s surface roughness was measured and recorded by the surface profiler (Model: TIME 3220). Fig. 2 shows the experimental device and Table 2 shows the grinding parameters in this experiment.