Surface grinding

Surface grinding is used to produce flat accurate surfaces and can be carried out on all materials, hard or soft. There may he no other way of removing metal from a hardened workpiece, ft is normally considered a finishing operation, hut large machines are used in place of milling and shaping machines to remove large amoimts of material. 

A typical surface grinder is shown in Fig. 10.1 and uses a 300 mm diameter by 25 mm wide grinding wheel. The reciprocating table and cross-slide movements are hydraulically operated, although alternative hand operation is provided. 

Copyright 2010 Bruce J. Black. Published by Elsevier Ltd. All rights of reproduction in any form reserved. 

The capacity of such a machine is the maximum length and width of surface which can be ground, in this case 500mmx200mm, and the maximum height which can go under a grinding wheel of maximum diameter. Using a 300 mm diameter wheel, the maximum height of workpiece on the machine shown is 400 mm. 

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Figure 10.28 shows a complete ACGIH VS-Print for an LVHV nozzle applied to a surface-grinding machine. The figure illustrates an adjustable LVHV nozzle positioned near the point of gtinding. Additional details are provided... 

FIGURE 10.28 ACGIH VS-Print for designing an LVHV exhaust nozzle for a stationary surface grinding machine. 

F. F. L. Morgan. Dust extraction systems for surface grinding wheels. U.S. Patent no, 2 819 571. W ashington, DC Patent Office, 1958. 

Fig. 9.23 Welded areas of an offshore platform structural tubular displaying premature corrosion due to (a) lack of surface grinding (resulting in poor paint adhesion and performance) and (b) the fact that the weld metal is anodic relative to the parent material of the tubular...

The corrosion process is modified by the physical state of the surface. Grinding and polishing processes, in particular, leave the structure in a more open state and with a degree of roughness and residual stress all can contribute to accelerated corrosion. 

Figure 10.31 The surface grinding process where a grinding lathe removes excess hard facing material from the outside diameter of the screw (courtesy of Jeffrey A. Kuhman of Glycon Corporation)...

Jeong, B.G., S.M. Yoon, C.H. Choi, et al. 2007. Performance of an electrochemical COD (chemical oxygen demand) sensor with an electrode-surface grinding unit. J. Environ. Monit. 9 1352-1357. 

Figure 11.18 a) Transformation zone ahead and around crack tip. (6) Surface grinding induces the martensitic transformation, which in turn creates compressive surface layers and a concomitant increase in strength. 

It is worth noting that the transformation can be induced any time the hydrostatic constraint of the matrix on the metastable particles is relaxed. For example, it is now well established that compressive surface layers are developed as a result of the spontaneous transformation. The process is shown schematically in Fig. 11.18. The fracture strength can be almost doubled by simply abrading the surface, since surface grinding has been shown to be an effective method for inducing the transformation. Practically this is important, because we now have a ceramic that, in principle, becomes stronger as it is handled and small scratches are introduced on its surface. 

Grinding Internal grinding External grinding Surface grinding flat bottom volume... 

C1495-01 Test Method for Effect of Surface Grinding on Flexure Strength of Advanced Ceramics... 

The main elements of a typical surface-grinding machine are shown in Fig. 10.2. 

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