Wearing of tools

Another hazard of compressed air is that it contains dust (organic and inorganic), water, and traces of hydrocarbons, which if they are not removed can cause excessive wear of tools or contamination of products. Morris writes, Those who use air for pneumatic tools or even paint spray seem to have an inbuilt resistance to any idea that the quality of their compressed air is of any serious consequence. The fact that it transmits concentrated quantities of abrasive particles and water into the finely machined orifices and cylinders of their tools seems to pass them by [12]. 

Bouzakis K-D, Mirisidis I, Michailidis N, Lili E, Sampris A, Erkens G, Cremer R (2007) Wear of tools coated with various PVD films correlation with impact test results by means of FEM simulations. Plasma Process Polym 4(3) 301-310... 

Friendly processing, no wear of tools andno skin irritation Restricted maximum processing temperature... 

Fukuda et al [2] used cathodic protection by imposed current to control wear of tools used for boring of wet wood. For this, they pressed a steel plate on one side of the wood workpiece. Care was taken to electrically insulated the steel plate from the frame of the boring machine. A DC power supply was used to pass a current ranging approximately from 1 to 30 mA from the tool (negative pole) to the plate (positive pole) through the wet wood. Tool evaluations after a constant number of drilled holes showed a reduction in wear up to a factor of 3 depending on the current passed. This was observed for cemented carbide, high-speed steel and alloyed steel tools. 

Exa.mina.tlon, The technical examination of stone objects begins with the use of the low power stereomicroscope. This study yields information regarding toolmarks and, hence, cutting techniques, wear patterns, and wear of toolmark edges. Such information is clearly significant in authenticity studies, but also provides an insight into the skill and the tools of the carver. 

A practical difficulty which arises during injection moulding of reinforced plastics is the increased wear of the moulding machine and mould due to the abrasive nature of the fibres. However, if hardened tool steels are used in the manufacture of screws, barrels and mould cavities then the problem may be negligible. 

D. of tool joints Shown for class 2 drill pipe are based on drill pipe having all the wear on one side and a minimum wall thicxnass of 65%. 

The third part identifies and describes the present and potential applications of CVD in semiconductors and electronics, in optics and optoelectronics, in the coating of tools, bearings and other wear- and corrosion-resistant products, and in the automobile, aerospace, and other major industries. 

Chemical vapor deposition (C VD) is a versatile process suitable for the manufacturing of coatings, powders, fibers, and monolithic components. With CVD, it is possible to produce most metals, many nonmetallic elements such as carbon and silicon as well as a large number of compounds including carbides, nitrides, oxides, intermetallics, and many others. This technology is now an essential factor in the manufacture of semiconductors and other electronic components, in the coating of tools, bearings, and other wear-resistant parts and in many optical, optoelectronic and corrosion applications. The market for CVD products in the U.S. and abroad is expected to reach several billions dollars by the end of the century. 

The wear and subsequent failure of a cutting tool is a complex mechanism that usually involves a number of physical and chemical phenomena. Temperatures at the tool/workpiece interface (cutting edge) may reach up to 1200°C in a very short period of time. This creates a pronounced thermal shock and promotes oxidation of the tool surface and the diffusion of metallic constituents of the tool into the chip with a resulting loss of tool strength. 

Other wear mechanisms are flank wear and crater wear which occur mostly with cemented-carbide tools. Flank wear refers to the depression that is formed below the cutting edge on the side of the tool caused by the abrasive wear of the cemented carbide. TiC is particularly effective in reducing it. Crater wear occurs in the form of small depressions on the rake face behind the point of contact of the tool with the workpiece. Diffusion of the cobalt binder into the cutting chip usually occurs with crater wear. TiN is effective in reducing both diffusion and crater wear.PI... 

Figure 18.1. Wear of coated and uncoated ceramic tools.

In order to study microscale friction and wear, scientists have developed the friction force microscope (FFM), nanoindentation and nanoscratch tester which serve as excellent tools in micro tribological research [1,6-9]. In this chapter, we first compare the differences between macro and micro friction and wear, and then introduce some results of our research group on microscale friction and wear of ordered films, thin solid films, and multilayers. 

The FFM based on the atomic force microscopy (AFM) is the most available tool to study the feature of microscale friction and wear of material surface with high resolution [6]. So the... 

It must be noted that the real-time aspect is important because tools are changed in the magazines of machines (or cells), not only because they wear, but also because different part programs may need different sets of tools. (The actual tool-changing operation is done in most cases by manipulators or by robots. The tool magazine loading/unloading procedure is performed mostly by human operators, sometimes by robots or special-purpose mechanisms, such as a tool shuttle.)... 

Most plastic parts are manufactured using shaping operations. Here, the material is deformed into its final shape at temperatures between room temperature and 350°C, using wear resistant tools, dies and molds. For example, an injection mold would allow making between 106 and 107 parts without much wear of the tool, justifying for the high cost... 

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