In oxidic glasses, both covalent and ionic bonds predominate. They generally display strong polarisation, which also causes its characteristically brittle removal behaviour. Should material shifting lead to the fracture of these bonds, the structure of glass is destroyed irreparably as opposed to metals, the free electrons of which can form new bonds. Figure 4-18 shows […]
Рубрика: Manufacturing Processes 2
Between Centres
Here, we must differentiate between two methods. In external cylindrical peripheral plunge grinding (infeed grinding), the grinding wheel is arranged normally to the workpiece rotation axis, while in external cylindrical peripheral longitudinal grinding the grinding tool is moved equidistantly to this axis. Both grinding methods generally work with up grinding. In up grinding, the vectors […]
Natural Diamond
Diamond is chemically pure carbon that crystallises as a natural product under extreme pressure and heat over a long period of time. About 80 % of natural diamonds are rejected for use as decorative objects because of their small size and deficient purity, making them available to industry. Their properties are nearly identical to synthetic […]
Material Properties as a Function of Heat Treatment
The amount, form and arrangement of the structural elements and thus the mechanical properties of steel can be adjusted to the requirements at hand by means of a defined heat treatment. Heat treatment is understood as a process in the course of which a workpiece or a workpiece section is exposed to defined temperature sequences […]
Grinding
5.2 Preparation Grinding tools are not in a usable condition as delivered or after a longer period of use. Grinding wheels exhibit macrogeometrical faults (e. g. roundness deviation, waviness, macro-wear, loss of profile), which lead to problems in the grinding process or to deficient dimensional accuracy of the components worked upon. Micro-wear, i. e. dulling […]