1. Introduction
1.1 Definition
High speed machining (HSM) enables an increase in efficiency, accuracy, productivity and quality of work-pieces as well as a reduction in costs and completion time compared to conventional machining. [1, 2]
HSM can trace back to early twenties of 20th century. However, the definitions of HSM are varied and complicated. The first definition is proposed by Carl Salomon in 1931. Salomon’s theory is that the chip-to-tool temperature will begin to decrease at a certain cutting speed which is 5 to10 times higher than conventional machining speed as shown in Figure 1. [1, 3]
Figure 1 Salomon's theory
Nowadays, one popular definition of HSM is based on the DN ratio, which means the bearing bore diameter (mm) multiplied by the maximum spindle speed (rev/min). For high-speed machining, the typical DN ratio is between 500,000 and 1,000,000. Moreover, HSM generally refers to end milling at high rotational speeds or surface speeds as shown in Figure 2.
Figure 2 High Speed Machining
HSM means utilizing cutting speed significantly higher than conventional machining speed. Generally, a specific range is used to quantitatively define machining speeds, which is shown as follows. [4]
• High speed machining : 600-1,800 m/min,
• Very high speed machining: 1,800-18,000 m/min,
• Ultra high speed machining : >18,000 m/min.
The range of high speed milling is shown in Figure 3.
Figure 3 Range of high speed milling
There is a comparison between conventional machining and high speed machining shown in the table.
Parameters Conventional HSM
The tool/workpiece contact time Long Short
Accuracy Low High
Cutting force High Low
Surface finish Low High
Material removal rate Low High
Cutting fluid Need No need normall...
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Machining processes are fundamental and essential steps in manufacturing engineering. HSM as a modern technology can bring about a dramatic increase in efficiency, accuracy, productivity and quality of work-pieces as well as a reduction in costs and completion time. However, there are some disadvantages of HSM, which require to be overcome to realize scientific and economic benefits in a better way. Therefore, the potential improvement is proposed, such as the multi-purpose coatings as well as the combination with AR to become smart HSM. Additionally, it is of vital importance to hold and balance the tool properly to ensure the best performance. With the potential development in the future, HSM can find more applications in manufacturing engineering, and generate more perfect products in a more safe and effective method and finally contribute to the society.
The straight-edge blade will be useful for many purposes both in everyday occurrences and outdoor use, but the lack of a sawing ability makes it less useful ...
But the grain size ranges between 3 μm to 6 μm, 3 μm to 8 μm and 4 μm to 9 μm for 4 mm, 6 mm and 8 mm plates respectively. Higher polygon pin face edges approach circular pin, this vanishes the pulse formation in stirring. This leads to distorted grains due to decrease in dynamic area or lack of sweeping between tool and material. Whereas a low number of polygon pin face edges generates higher dynamic area. This shows the coarse grains relatively. The grain size ranges between 5 μm to 7 μm, 6 μm to 8 μm and 7 μm to 9 μm for 4 mm, 6 mm and 8 mm plates
Fabrication at the factory utilizes a mix of robotics and manual labor to produce the body of the V-Rod. Robots that are designed to cut pipe are capable of completing a single operation within 3 seconds. Other fabrication robots utilize 1800 watt lasers that can perform cutting operations at the rate of 100 inches per minute. Where robotics can be used to perform high speed cutting and welding operations, skilled workers are a...
War has been a recurring part of America’s history for the past hundreds of years. From the 1700s to the present, America has gotten into numerous situations and turmoil, which eventually lead to the wars we currently study and know about today. Technological advancements in warfare were necessary and a great obligation during times of war. This was pursued with drastic improvement. From the transformation of the use of smoothbore muskets during the Civil War to the industrial revolution leading to weaponry innovations post civil war, the nature of warfare dramatically changed. These developments proved to be proficient in battle. In the midst of these hundreds of years, while many technological advances demonstrated to be efficient in battle, the machine gun was one of the most significant advancements in technology that changed the face of warfare through its transformation of operations and strategy.
Life cycle - The life cycle of a photo chemical machining tool is estimated to be around 450 cycles. For a large volume production it is often advisable to produce a negative master film, this also a positive film to be quickly produced by a contact method. It is advisable where the design of a component allows, to avoid manufacture of a tool that produces large areas of photo resistant removal. If the work material has areas of exposed metal the machine will have a faster rate of etch than cutting lines, this can cause tolerance problems together with a faster contamination of the etching chemistry.
It is thus a thermal erosion process. The sparks are created in a dielectric liquid, generally water or oil, between the work piece and an electrode, which can be considered as the cutting tool. There is no mechanical contact between the electrodes during the whole process. Since erosion produced by electrical discharges, both electrode and work piece have to be electrically conductive. Thus, the machining process consists in successively removing small volumes of work piece material, molten or vaporized during a discharge. The volume removed by a single spark is small, in the range of 10-6-10-4 mm3 but this basic process is repeated typically 10,000 times per
If you haven’t tried a claw machine before, then good for you, if you haven't, then you probably know how it seems impossible to actually get anything from it. Either the machine’s claw seems like it doesn't have enough power to grab even a feather, or when it actually does manage to pick something up, by the time it almost reaches the toy chute, it tricks you into thinking you almost got it and drops the toy just a few centimeters short. Last summer, a friend and I were at an arcade, and there was a claw machine filled with plush toys. So my friend goes and inserts a few quarters and the machine starts up.
Machine Manufactering: Diamond tools are used to cut parts down to the right size so that they can be used in machines.
There are different kinds of chips produced from machine tools and we should know what chips are produced so as to get the best use out of our machine by selecting appropriate components for the same.
As the name of this group of abrasive operations suggests, their objective is to achieve superior surface finish up to mirror-like finishing and very close dimensional precision. The finishing operations are assigned as the last operations in the single part production cycle usually after the conventional or abrasive machining operations, but also after net shape processes such as powder metallurgy, cold flashless forging, etc. The finishing processes discussed in this section include honing, lapping, superfinishing, polishing, and buffing. Honing is a finishing process performed by a honing tool, which contains a set of three to a dozen and more bonded abrasive sticks. The sticks are equally spaced about the periphery of the honing tool. They
It is also necessary to take into account the consequent restrictions of the manufacturing process. This means that the firewall and seat geometry needs to be designed considering the characteristics and limitations of the 5D CNC milling machine (used to obtain the milling models) and the Mould.
If you have no idea what that means, picture it this way. Imagine if while turning a screw, you started tapping it with a hammer; the screw would go in faster. That is essentially what an impact driver does. An impact driver hammers a screw around 50 times a second, which produces upwards of 5 times more torque than your average cordless drill. So, if you are having issues getting a screw through tough material, then you may want to try swapping out a cordless drill for an impact driver.
Silicon surface micromachining uses the same equipment and processes as the electronics semiconductor industry. There are three basic building blocks in this technology, which are the ability to deposit thin films of material on a substrate, to apply a patterned mask on top of the films by photolithographic imaging, and to etch the films selectively to the mask. A MEMS process is usually a structured sequence of these operations to form actual devices.
“What is Laser Cutting and How is it Used in Metalworking?”. Nmfrings. National Metal Fabricators, 2011. Web. 25 May 2014.
Abrasive Jet Machining (AJM) is the removal of material from a work piece by the application of a high speed stream of abrasive particles carried in gas medium from a nozzle. The AJM process is different from conventional sand blasting by the way that the abrasive is much finer and the process parameters and cutting action are both carefully regulated. The process is used chiefly to cut intricate shapes in hard and brittle materials which are sensitive to heat and have a tendency to chip easily. The process is also used for drilling, de-burring and cleaning operations. AJM is fundamentally free from chatter and vibration problems due to absence of physical tool. The cutting action is cool because the carrier gas itself serves as a coolant and takes away the heat.