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Introduction
Published in Zainul Huda, Machining Processes and Machines, 2020
An abrasive machining process involves the use of a grinding wheel, an abrasive stick, or an abrasive suspension to remove material from a workpiece. Grinding is a material removal operation by the action of hard and abrasive particles that are bonded usually in the form of a wheel (grinding wheel). As indicated in Figure 1.2, a grinding operation may be surface grinding, cylindrical grinding, or center-less grinding. The abrasive finishing machining operations include honing, lapping, superfinishing, and the like. Grinding and other abrasive machining processes are explained in detail in Part III (Chapters 11 and 12).
Cutting Tools
Published in David A. Stephenson, John S. Agapiou, Metal Cutting Theory and Practice, 2018
David A. Stephenson, John S. Agapiou
Operational factors such as wheel balancing, truing/dressing, grinding cycle design, and coolant application also affect and are affected by grinding wheel selection. Wheel truing and dressing in particular have a strong impact on wheel performance and life. The truing operation removes material from the cutting face of the wheel to generate a particular profile (or to maintain a flat profile), to minimize wheel runout, and remove lobes or irregularities. Truing is necessary if the wheel runout exceeds 0.013 mm after mounting. The dressing operation conditions the wheel surface to maintain particular cutting characteristics; it removes loaded material and glaze from a dull wheel face [4,164] to control the surface finish of the workpiece. A smooth wheel face containing dulled grains is called glazed. In some cases, the same wheel is used for rough and finish grinding a part; in these cases the course wheel is dressed to generate dull grains so that it can produce a finish normally produced by a fine grain wheel.
Machining III—Shaping, Milling, and Grinding
Published in Zainul Huda, Manufacturing, 2018
Grinding involves material removal by the action of hard and abrasive particles that are bonded usually in the form of a grinding wheel (Figure 10.7). It is generally used as (rough) finishing operations after part geometry has been established by conventional machining.
Coolant condition and spindle power in high-efficiency-deep-grinding of nickel-based superalloy profile part
Published in Materials and Manufacturing Processes, 2022
Zhengcai Zhao, Ning Qian, Yucan Fu
High-efficiency deep-grinding (HEDG) can machine turbomachinery components, composing of difficult-to-cut materials, such as titanium alloys, superalloys, and intermetallic alloys, in the aerospace industry.[1–5] In addition, HEDG has a high material removal rate because it combines a large depth of cut (up to several millimeters) and a high grinding speed (up to 160 m/s). Large grinding parameters can cause serious grinding burn-out, which is one of the main issues that restricts its wide application in the industry.[5–8] To reduce the grinding burn, coolant is applied in the process for three purposes: cooling the workpiece and grinding wheel, lubricating, and flushing away the chips.[8–12] Two types of coolant are used in this industry: water-based cooling fluid for high cooling efficiency and washing away ability,[13,14] and oil-based coolant for high lubrication capacity.[14–17] Water-based coolants with good cooling effects are commonly used in the aerospace machining industry.
Scalable preparation of graphene from graphite ore via mechano-chemical ball milling
Published in Materials and Manufacturing Processes, 2022
Aswathy S Nair, Vasumathi Nallusamy, K. Jayasankar, Sreejakumari Ss
The synthesis method was mentioned elsewhere.[13] Horizonal planetary ballmill (Fig. 3) was used for the graphene synthesis by means of shear-mechanical exfoliation. Mill is provided with two driving system, one attached to the jar and other to the disc holding the jar and both having different control system. The purified graphite was mixed in a stainless-steel container with stainless steel balls of 10 mm diameter in a 5:8 ratio. The milling was carried out in wet condition using toluene as agent. During the process, reagent molecule adsorption on the graphitic surface can effectively weaken van der Waals interactions between graphite layers, and energy is supplied by ball milling, which can facilitate graphene sheet exfoliation from graphite. Impact, frictional, and shear forces arising from ball-to-wall and ball-to-ball collisions handle the samples quickly and efficiently. A variety of factors affect the grinding outcome, including the mill’s rotation speed, the grinding time, the sample-to-ball filling ratio, and the material of the grinding components. Critical speed (CS) was optimized for maximum exfoliation and comparatively less defects. The milling was carried out for 4.5, 7, and 10 h with 1 h per cycle rest time. The grinding bowl filling is subjected to not only gravitational forces, but also Coriolis and centrifugal forces, which increase the kinetic energy of the grinding components by up to 100 times the gravitational forces. The obtained graphene was stored prior to use. The entire experimental procedure is illustrated in the flowchart (Fig. 4).
Application of eco-friendly lubricants in sustainable grinding of die steel
Published in Materials and Manufacturing Processes, 2021
Akash Subhash Awale, Meghanshu Vashista, Mohd Zaheer Khan Yusufzai
The precision manufacturing industries can only sustain in a present competitive world if it manufactures excellent quality components at low production cost. Among various machining processes to produce a high surface finish and closer dimensional tolerance components, the grinding process is most preferable choice. Besides, a significant heat was generated in the machining area due to simultaneous shearing, rubbing, and plowing action of unevenly distributed abrasive grits.[1] Approximately 80% of the generated heat gets transferred into the work material, particularly for “difficult-to-machine” materials, including nickel alloy and die steel, due to their low thermal conductivity.[2] The surface quality and grinding wheel life are usually assessed in terms of thermal damage, phase transformation, and wheel loading characteristics.[3] Hence, huge expenditure is spent on cutting fluid in the grinding domain to provide sufficient lubrication and extract the excess heat from the cutting zone. These fluids contain problematic organic contaminants, which may induce various diseases to humans like skin cancer and respiratory tract, and create a threat to the environment.[4] To overcome these issues, sustainable grinding is recently introduced in manufacturing to finish a “difficult-to-machine” material without polluting the water and soil. This can be best accomplished by using a negligible amount of coolant with effective cooling and lubrication, i.e., small quantity lubrication (SQL).