A Low Temperature Method for Fabrication of Dense Boron Carbide Composites

Category-

Advanced materials and Manufacturing

Industry Classification:

NIC (2008)- 23935- Manufacture of ceramic laboratory, chemical and industrial products
NAICS (2022)- 327110- Pottery, Ceramics, and Plumbing Fixture Manufacturing; 339113– Bulletproof vests manufacturing
Applications– Manufacturing of Neutron absorber, Body Armor material, Blast nozzles, cutting tools, control rods

Market Drivers-

From 2023 to 2033, the boron carbide market is projected to exhibit a 5.3% CAGR. It is anticipated to rise at a valuation of US$ 153.9 million in 2023

Processing of Boron carbide is extremely difficult due to its covalent nature and low diffusion coefficient.
It requires high temperatures (> 2100 °C) and pressures (30-40 MPa) for densification.
Such processing conditions are expensive and also favor grain coarsening which degrades the mechanical properties.
There is a need for an improved approach for low temperature sintering processes for fabricating dense B4C components.

The process consists of sintering of B4C composite at Spark Plasma Sintering (SPS) temperature of 1400°C and 50 MPa pressure using mechanically activated Ti-B as sintering aid
Mechanical activation of Titanium and Boron powder in the ratio 5:95 (by weight) followed by ball milling for 4h for homogeneity and better dispersion
Spark plasma sintering was carried out at 1400 ˚C with a heating rate of 100 9 ˚C/min and hold time of 10 min at peak temperature with 50 MPa pressure.
The grain size of the Boron carbide obtained was approximately 15-20 μm with no porosity
The hardness of the sample measured form Vickers micro hardness tester was ~29 GPa

The invention enables fabrication of B4C composites at 1400°C compared to conventional technologies that require a minimum temperature of 1700°C.
The calculated theoretical density of the composite is 3.27 g/cc while the measured density of 3.35 g/cc indicates that the achieved density is almost same as the theoretical density. Whereas, prior art processes have reported achievement of only 95-98% of theoretical density.
Fine grain size and no porosity enhance suitability of the obtained composites for high performance applications.
The low temperature process reduces fabrication costs without compromising on mechanical properties.

Prof. Srinivasa Rao Bakshi

Department of Metallurgical and Materials Engineering

TRL – 4

Technology validated in lab scale.

Technology Transfer