Influence of joining time and temperature on the flexural strength of joined boron carbide ceramics

Abstract

The influence of the joining time and temperature on the flexural strength of B 4 C ceramics joined using an Al sheet was investigated. The B 4 C ceramics were joined over a temperature range 6001400°C for 272 h in vacuum (10 ¹2 10 ¹4 Pa) and in an Ar atmosphere. A joining interlayer with a dense structure was found in the B 4 C joint formed at 1000°C after 2 h in vacuum, and mainly Al was present in this joining interlayer. On the other hand, some voids existed in the joining interlayer in the B 4 C joint formed after 72 h. In addition, Al was not present in this interlayer owing to its reaction with B 4 C as well as the evaporation of Al. Four-point bending tests of the B 4 C joints formed at 1000°C in vacuum for periods ranging from 2 to 72 h were performed at room temperature. The average four-point bending strengths of the B 4 C joints formed after 2 h at 7001100°C were close to that of the B 4 C base material, and the B 4 C ceramics were considered to have successfully bonded. However, the joint strength decreased with an increase in the joining time, and the B 4 C ceramics did not bond at temperatures over 1200°C in vacuum. On the other hand, the B 4 C ceramics did bond at 12001400°C in Ar.

Influence of Joining Interlayer on Impact Damage to Laminated Boron Carbide Ceramics

“…b, some new phases were found to be present within the interlayer, which is demonstrated by the color contrast. The reaction between B 4 C and Al in the joining interlayer has been reported in our previous study in detail . However, the joining interlayer obtained under the conditions used in the present study was found to mainly consist of Al.…”

“…In addition, the reaction between B 4 C and Al, and the contact angle of liquid Al on a B 4 C ceramics have been studied extensively, that liquid Al is easy to react with B 4 C, and some reaction mechanisms are reported between B 4 C and Al . Therefore, in our previous study, the technique of joining B 4 C ceramics was studied and B 4 C ceramics were successfully joined using Al sheets . The flexural strength of the B 4 C joint was found to be similar to that of the B 4 C base material because of the dense and crack free interlayer.…”

Aluminum Electrodeposition on the Surface of Boron Carbide Ceramics by Use EMIC–AlCl3 Ions Liquid

“…Kita et al [7,22] showed that the penetration of pure Al film with the direct coating method into cracks improves the mechanical properties of the material. In our previous study [23], the method employed by Kita et al was used to obtain coatings; however, it was limited because of some complicated parts.…”