Samples of different B/C ratios were mixed in a laboratory-type ball mill. The mixtures were passed though a 325 mesh sieve and then transferred to graphite foil boats. They were heated in a tube furnace at 1150 to 1450°C for  2hr under Ar atmosphere. Using this procedure, samples containing up to 89% boron carbide (B4C) were obtained. Boron carbide powders with purities up to 99% and average grain sizes under 10 µm were obtained through purification stages.

Carbide ceramics such as boron carbide due to their unique properties such as low density, high refractoriness, and high strength to weight ratio have many applications in different industries. This study focuses on direct bonding of boron carbide for high temperature applications using nickel interlayer. The process variables such as bonding time, temperature, and pressure have been investigated. The microstructure of the joint area was studied using electron scanning microscope (SEM) technique. At all the bonding temperatures ranging from 1150 to 1300°C a reaction layer formed across the ceramic/metal interface. The thickness of the reaction layer increased by increasing temperature. The strength of the bonded samples was measured using shear testing method. The highest strength value obtained was about 100 MPa and belonged to the samples bonded at 1250 for 75 min bonding time. The strength of the joints decreased by increasing the bonding temperature above 1250°C. The results of this study showed that direct bonding technique along with nickel interlayer can be successfully utilized for bonding boron carbide ceramic to itself This method may be used for bonding boron carbide to metals as well.

Boron carbide - silicon carbide composite was produced by mechanically activated combustion synthesis (MASHS) method, in this study. Initially, raw materials powders containing B2O3, Si, C and Mg were weighed and were milled under Ar atmosphere by a planetary mill. For prepare pellets, the milled powders were pressed by uniaxial cold press and synthesis was occurred in atmosphere controlled tubal furnace. In the various steps, XRD analysis was taken to check the phases. XRD analysis used to calculate the average crystalline size and SEM and TEM analysis were taken to morphology studying. Resulting product is contains MgO, B4C and SiC. Also in the XRD analysis little chance existence of Mg2SiO4 or borate compounds of magnesium and remaining boron, carbon and silicon are outstanding. In order to remove or reduce undesired phases, acid leaching by hydrochloric and mechanical activation with different energies were performed. The study of X-ray diffraction analysis after acid leaching showed great influence of acid leaching by HCl to remove impurities. It was also seen that remaining substances significantly reduced by activation energy increases. Average crystalline sizes of optimal sample were calculated by Scherrer equation by 11.09 for B4C and 12.66 for SiC. The SEM and TEM analysis confirmed synthesis of nano scale boron carbide - silicon carbide composite in nano scale. Grain size of about 30 nm was observed by TEM.

Effect of adding boron carbide (B4C) particles to epoxy resin on dry sliding wear behavior was investigated. The weight percentages of 5 and 10 of B4C were homogeneously dispersed into epoxy resin in order to produce test samples. Tribological characteristics of the reinforced composite specimens were compared with the properties of pure epoxy resin. Wear tests were performed according to ASTM G-99. Taguchi L9 orthogonal array was used to obtain test pattern. The tests were conducted under three different loads of 5, 10 and 15 N, at three different velocities of 0. 8, 1 and 1. 2 m s−, 1 and at three different sliding distances of 750, 1000 and 1200 m. These tests were carried out under dry conditions at room temperature. Resulting data of each specimen were analyzed, evaluated and reported by qualitative and quantitative means. Metallurgical examinations were presented to assess the effect of B4C particles on the wear mechanisms. Friction surfaces of the test specimens were examined by scanning electron microscopy (SEM). The results were also compared with Taguchi predictive results. The most dominant parameter which affected the tribological properties was determined as B4C ratio. The enhancement of wear resistance was achieved with the addition of boron carbide reinforcement to epoxy resin.

In this study, boron carbide (B4C) nanostructures were prepared by using mechanical alloying method. B4C nanostructures were prepared using halogen salts, boron oxide and cobalt catalytic agent. The phase transformation and microstructure of powders during ball milling were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). SEM photographs of particle size distribution neatly formed into a nest of birds displayed. XRD studies indicated that the prepared particles were single phase crystalline B4C. The average particle size 25 nm was reported.

Al-B4C composites have attracted attention of a large number of researchers and industrial societies dealing with military, nuclear, transport, and computer fields. In this research, the structure of these composite materials produced by a method based on accumulative roll bonding (ARB) was considered. The results showed that applying a specific draft percentage of reduction of %66 during inserting the reinforcement layers and then that of %50, a desirable cold weld between the sheets is obtained. X-ray diffraction and transmission electron microscopy analyses revealed that after 7 ARB passes, nanostructures elongated in the rolling direction are developed. Furthermore, a suitable distribution of the reinforcing boron carbide particles in the nanostructured aluminum matrix was achieved after 7 ARB passes, suggesting the pleasant efficiency of the employed route.

The use of metal matrix composites can provide a combination of desirable properties of metals as well as the special physical properties of neutron absorber reinforcing particles such as boron carbide, which alone may be brittle. Therefore, in the present study on neutron attenuation power of composite shielding, several Al-B4C composite samples with weight fractions of 5, 10 and 20% B4C have been used. In order to investigate the neutron absorption properties of the studied samples, the MCNP Monte Carlo code and the neutron source of the dry channel of the MNSR reactor with a flux of 2. 13E+5 n. cm-2. s-1 have been used, which provided in nominal reactor power of 30 kW. The results show that the neutron flux in the presence of 5, 10 and 20% boron carbide samples is predicted to be 1. 32E+05 n. cm-2. s1, 1. 12E+05 n. cm-2. s-1 and 1. 07E+05 n. cm-2. s-1, respectively. With this increase in the percentage of reinforcement phase, neutron flux is reduced down to 50%.

Boron carbide, which has a high melting point, outstanding hardness, good mechanical properties, low specific weight, great resistance to chemical agents and high neutron absorption cross-section (10BX C, x〉4 x ) is currently used in high-technology industries for example, fast breeders, light weight armors, high-temperature thermoelectric conversion, wear resistance applications, e.g., as blast nozzles, wheel dressing tools and nuclear industry, e.g., shielding material and control rods etc.Boron carbide can be synthesized by a variety of high temperature methods, such as the direct reaction of carbon with boron; carbonthermal reduction of boron oxide (B2O3) over 1000ºC; reduction of  BCl3 by 4 CH at a temperature of 1500ºC with laser; thermal decomposition of a mixture of pure carbon and boron trilogies in an atmosphere of hydrogen; gaseous reaction between BCl3 and a methane-hydrogen mixture in r.f. argon plasma.The most commercially viable and industrial method is from reduction of boric acid with carbon black at a temperatures over 1750ºC .The product thus obtained is hard and consists of excess unreacted carbon. The hard mass is crushed and pulverized to the requisite mesh size and purified by chemical and thermal oxidation method because of their contamination from grinding media. In this work, boron carbide was produced from inexpensive raw materials such as boric acid (boron source) and citric acid (carbon source) by sol-gel method. Aqueous solution of boric acid in presence of citric acid forms a stable gel under controlled pH condition. The gel on subsequent pyrolysed under vacuum. The precursor from primary pyrolysis with stoichiometric composition was heated in a tube furnace under vacuum to 1250, 1350, 1450, and 1500ºC with a heating rate of 5ºC / min and held for 2.5 hr at temperature.XRD patterns were taken from the samples prepared at different temperatures. From the patterns, it was found that no reactions have occurred at 1250 ºC and the product contains B2O3 and C. By increasing temperature to 1350 ºC it looks that some reactions have taken place, but unreacted B2O3 and C are seen yet. t. Whereas, at 1450 and 1500 ºC no B2O3 is observed and the only impurity seen is C. This indicates that at 1450 ºC and higher temperatures the reaction is completed. From the SEM patterns it can be seen that the shape of the particles is somewhat between spherical and elliptical. The free carbon and particle size of the product were analyzed.

Boron carbide because of properties such as high hardness, high Young's modulus and low density is highly regarded, however due to difficulties in sintering ability, low fracture toughness and low oxidation resistance at temperatures greater than 1000oC, its application is limited relatively. Obtaining a high-density boron carbide by conventional methods is very difficult and costly because of the high melting point, covalently bonded, its low self-diffusion and high vapor pressure. Many of researches have been done to improve the sintering condition by different methods and using various kinds of sintering aids. It is often observed that small amounts of oxides have been more effective on sintering improvement of non-oxidizing ceramics. In this paper, the effect of different oxidizing sintering aids has been reported on sintering behavior and mechanical properties of boron carbide.