Electrochemical and X-ray Examinations of Erosion Products during Dressing of Superhard Grinding Wheels Using Alternating Current and Ecological Electrolytes of Low Concentration of Chemical Compounds

This article introduces significant cognitive and usable values in the field of abrasive technology especially in the development of new methods of the electrochemical dressing of superhard grinding wheels with metal bonds. Cognitive values mainly concern the elaboration of the theoretical backgrounds of the electrochemical digestion of compounds of grinding wheel metal bond and gumming up products of the cutting surface of grinding wheel (CSGW). Cognitive values also deal with determining the mathematical relationships describing the influence of technological conditions of dressing on shaping of cutting abilities of superhard grinding wheels. On the other hand, the useful values refer to the industry implementation of the elaborated method and equipment for the electrochemical dressing of suparhard grinding wheels using alternating current (ECDGW-AC). The cost of the device for the realization of this process is low and can be applied in the production conditions. The novel achievements presented in the article are: the elaboration of a new method and equipment for electrochemical dressing of superhard grinding wheels (ECDGW-AC), the selection of electrolytes of low concentration of chemical compounds, tests concerning the digestion of grinding wheel metal bond compounds and gumming up products of CSGW using X-ray analysis, as well as the determination of chemical reactions taking place during elaborated new dressing process, the elaboration of mathematical relationships describing influence of technological conditions of this process on dressing speed and shaping of cutting abilities of superhard grinding wheels, and the performance of technological tests of dressing of superhard grinding wheels using ECDGW-AC method. The elaborated method can be used in ambient temperature and does not cause thermal damages of abrasive grains of cutting surface of grinding wheel and is useful not only for dressing super hard grinding wheels but also for correcting their geometrical deviations.

Reductive elimination of [AlH2]+ from a cationic Ga-Al dihydride

Oxidative addition of TMEDA-supported [AlH2]+ to [{BDI}Ga] (BDI = {HC(C(CH3)N(2,6-iPr2-C6H3))2) provides [{BDI}Ga(H)-Al(H)(tmeda)]¬[B(C6H3-3,5-Me2)4] (TMEDA = N,N,N’N’-tetramethylethylene¬diamine) with a covalent metal-metal bond. The reaction is readily reversed by substituting TMEDA for an...

Exploring the stability of the NHC‒metal bond using thiones as probes

The metal−carbon bond in N-heterocyclic carbene (NHC) metal complexes, which are ubiquitous in modern homogeneous catalysis, is often conjectured to be robust. Here, carbene dissociation was evaluated from a series...

A RuII,III2 diphosphonato complex with a metal–metal bond for water oxidation

A water soluble and wide pH stability RuII,III2 diphosphonato complex with a metal–metal bond was applied to water oxidation.

INVESTIGATING THE PROCESS OF STRUCTURE FORMATION AND WEAR RESISTANCE OF ABRASIVE TOOLS ON THE METAL BOND OF COMPOSITION 51%Fe+9%Ni 32%Cu+8%Sn MADE OF METALLIZED BY TITANIUM DIAMOND POWDERS

The process of of structure formation and wear resistance of abrasive tools on the metal bond of composition 51%Fe+9%Ni+32%Cu+8%Sn made from metallized by titanium diamond powders is investigated. The metallographical substantiation is introduced, as well as the wear-resistance and the working capability of abrasive tools are studied. It is shown that the structure is heterophase and consists of five phases, the first of which is a solid solution based on nickel, the second is a solid solution of tin, nickel, and iron in copper, the third is a solid solution of nickel, copper and tin in iron, the fourth and the fifth are intermetallic compounds with a defective structure. It is revealed that in the developed composite material, the volume content of heavy components is approximately 63%, the plastic component occupies approximately 25% of the sample volume, and the intermetallic phases - approximately 12% of the total volume, which are distributed over the entire sample surface. Based on the results of the complex investigation of the operability and wear resistance of diamond tools manufactured according to the developed technology carried out in the laboratory and production conditions for processing non-metallic materials, the optimal modes of manufacturing highly productive and wear-resistant diamond-metal abrasive tools were selected and substantiated: cold pressing pressure P = 600 MPa, free sintering temperature: T = 850°C, holding at this temperature: τ = 45 min. Applying the developed technology as a method for producing a diamond tool ensures the high efficiency of production.