Хонинговальные головки

2.4.1 Chemistry, Types and Characteristics of CBN The invention of the superabrasive cubic boron nitride (CBN) is linked closely to the synthesis of artificial diamond. CBN has the same crystal structure as diamond (cubic zinc blende structure), but the carbon atoms are replaced by the elements boron and nitrogen (Fig. 2.19 left). Boron nitride (BN) Read more

The hardening process has to follow a defined temperature program (examples given in Fig. 3.8). Several chemical processes happen during curing depending on the actual temperature [COLL88, GARZ00, p. 331]: • 70-80 °C: The resin bond starts to flow and to transform into a fused mass. Water in the phenol resin evaporates and the resin Read more

Binders for pastes include the following [MARI04, p. 442 f., BORK92, p. 24]: • Stearin—stearic acid, CH3(CH2)16COOH, white, solid, crystalline substance, melting point of 140 °C; Stearin is a good binder and brings cohesion and hardness to the paste. • Oleic acid—olein, unsaturated fatty acid, melting point of 15 °C; Oleic acid accelerates the polishing Read more

Pores are necessary for the transport of cooling lubricant to and chips away from the cutting point. They become more critical for high material removal rates and high-speed grinding processes to get enough cooling lubricant into the grindinggap. Grinding wheels with discontinuous cutting faces have similar effects as highly porous wheels [BORK92, p. 36]. Porosity Read more

Section 7.1 described different methods for evaluating sustainability and Sect. 7.2 derived the life cycle inventory for grinding to implement these methods. Data for the analysis is either measured empirically, estimated or obtained from databases. Ideally, fundamental process knowledge would allow calculating all input and output streams from physical and analytical models. The following study Read more

This thesis was written mainly during my time as postdoc researcher at the Werkzeugmaschinenlabor (WZL) at the RWTH Aachen University, and at the Laboratory for Manufacturing and Sustainability (LMAS) at the University of California Berkeley. The research on the life cycle engineering of abrasive tools was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) Read more

Today, grits are available in a large range of toughness suitable for many appli­cations [MARI04, p. 347]. Hard and friable abrasives are generally applied in precision grinding, whereas tough, large grits are more suitable for heavy-duty grinding [MALK08]. Grit types for resin bonds are usually more friable than for bronze bonding [BUTT68, p. 73]. Toughness Read more

Metallic bonding by infiltration is used mainly for dressing rollers and special applications [KLOC09]. Infiltrated bonds are also used for superhard honing sticks (bronze, Co-bonding), stone drilling crowns, or saws. Grits, bond, and fillers are either mixed and filled into the die or the grits are fixed first onto the bottom of the die form Read more

In general, the recycling or re-use of grinding tool components takes place in very few instances, although it is technically feasible in many cases. The reason lies in cost considerations. Today, the costs of recycling and re-use are higher than the benefits. This might change in the future because the decision is volatile and depends Read more

Malkin defines attritious wear referring to the development and growth of wear flats on the tips of active grains. Attritious wear is measured by the percentage of the wheel surface covered with wear flats [MALK68, p. 36]. Jackson defines attritious wear as wear that occurs “atom by atom” by physical and chemical interaction between grain Read more