É. V. Prilutskii

Investigation of the Structure and Properties of Materials in the SiC ― TiB2 System

The structure and properties of sintered and hot-pressed materials of the SiC ― TiB2 system were investigated. The optimal conditions for obtaining dense ceramics with minimum grain size of the phase components was determined. It was established that composites containing from 25 to 50 vol.@percnt; TiB2 have a bend strength equal to 450 MPa at 20°C; this increases to ∼500 MPa at 1600°C for ceramics with a pseudoeutectic structure. The material is highly heat resistant in the temperature range 900-1200°C.

Structure and Properties of Ceramics Based on Tungsten and Titanium Borides and Boron Carbide

The W2B ― TiB2 ― B4C ceramics studied were hot-pressed from composite powders synthesized by thermal reduction of boron carbide. The resulting materials have a skeleton structure with a boron carbide binder when the B4C content is high and an inclusion-matrix structure when the B4C content is low. The grain size varies from 5 to 20 μm, depending on the preparation conditions. The composite has a hardness of 17.5-20 GPa with a strength in the range 500-1000 MPa.

Some features of the milling and pressing of boron carbide

ConclusionsA study of the process of comminution of technical boron carbide in a magnetic eddy unit and a planetary activator has demonstrated that experimental plots of the specific surfaces of powders vs milling time are described by Khodakovs equation. The effectiveness of milling of boron carbide is an order higher in a planetary activator than in a magnetic eddy apparatus. However, in a planetary activator the process is accompanied by more intense pickup of iron. The process of densification of boron carbide powders produced by different methods is described by a logarithmic plot of relative volume vs pressing pressure.