Хонинговальные головки

A high degree of hardness and toughness and high amounts of stability and ther­mal conductivity are the primary requirements placed on an abrasive grit. These properties are influenced by chemical composition, crystal structure as well as by the grit size. In table 3-2, the main components of various types of corundum and their most important […]

In order to produce rubber bonds, natural and synthetic rubbers are mixed. To this mixture, sulphur is added as a vulcanisation agent. The sheet is produced by means of a multistage rolling of the abrasive grits. The rolling process is repeated several times, in the course of which the very heavy sheets are tuned by […]

Steel materials are categorised according to their alloying elements, their struc­tural components and their mechanical properties. Such a classification of steel materials is helpful in the selection process with respect to functional properties and in the determination of machining conditions. Classification according to alloy content leads to the following categories: • unalloyed steels, • low-alloyed […]

With respect to their material characterisation, ceramics are subdivided into oxide, non-oxide and silicate ceramics. In the case of oxide ceramics, aluminium oxide and zirconium oxide or zirconia (ZrO2) represent the industrially most importantmaterials. Oxide ceramics have mostly ionic bonds (> 60 %), exhibit favourable sintering properties and are disadvantageous compared to other ceramics with […]

One method which is frequently employed because of its flexibility is profiling with silicon carbide grinding wheels. This method can be used for all dressable bond types and is especially popular for profiling diamond grinding wheels. The basic forming mechanism is based on the abrasive effect of silicon carbide on the grinding wheel bond. Here, […]

External cylindrical grinding is primarily used for machining rotation-symmetrical workpiece contours and is subdivided by the type of workpiece positioning and main feed directions (Fig. 6-34). Fig. 6-34. External cylindrical peripheral grinding In the case of external cylindrical grinding between centres, the workpiece is clamped in frontal centring components and impelled by means of a […]

Silicon carbide is a technical product that is melted from quartz sand in a resis­tance arc furnace. In this method, silicon carbides of varying purity, toughness and colour can be produced by altering the process, as is the case for corundum. Pro­ceeding from the colour, we differentiate between green silicon carbide and black (dark) silicon […]

In order to appraise and examine grinding wheels, numerous requirements are placed on the testing method used. The most important are that the testing method is damage-free, is independent of the attendant and provides reproducible results. These requirements are oriented by the conditions of the call for proposals of the Vereins Deutscher Werkzeugmaschinenfabriken e. V. […]

Case-hardened steels include unalloyed construction steels, grade and special steels as well as alloyed special steels. Common to all of these is a relatively low carbon content (C < 0.2 %). Typical carbon contents and alloying components of case-hardened steels are represented in table 4-2. Element C Si Mn P S Amount in % 0.07 […]

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 […]