Microstructure and Mechanical Properties of Ti-B-N Cast Alloys Prepared by Reactive Arc-Melting

Abstract

Ti-B-N cast alloys were prepared by a reactive arc-melting technique using elemental titanium and boron nitride powders. The alloys obtained were composites of titanium matrix containing nitrogen of 3 mol% or less and a small amount of TiB reinforcement. The microstructure of the matrix was a cellular structure consisting of elongated dislocation cells with 1-2 µm in width and 5-10 µm in length, for Ti-1B-1N alloy. The TiB particles were rod-like in shape with size of less than 0.5 µm in diameter and agglomerated to form clusters along the grain boundary. The mechanical properties were mainly dependent on the content of nitrogen and the influence of TiB on the mechanical properties was relatively small. The Ti-B-N cast alloys containing suitable concentration of nitrogen, Ti-0.5B-0.5N alloys, had a high strength of 920 MPa with adequate ductility of more than 5%.

Microstructure and wear of in-situ Ti/(TiN + TiB) hybrid composite layers produced using liquid phase process

“…The titanium borides, especially TiB, are reported to form in a hexagonal pillar shape [26]. Morikawa et al [32] found clusters of TiB particles with rod-like shape along the grain boundary in the cast Tie1Be1N alloy. In the present work, relatively smaller features were observed; this is attributed to higher cooling rate of TIG compared to cast processing.…”

Microstructure and mechanical property of TiB reinforced Ti matrix composites fabricated by ultrasonic vibration-assisted laser engineered net shaping

“…Reactive hot pressing (RHP) and casting processes have been reported to fabricate TiB-TMC parts to near net shapes. The effects of tailored microstructures on the mechanical properties have been investigated in both processes (Huang et al , 2012; Morikawa et al , 2002). These two traditional processes fabricate structure-restricted TiB-TMC parts with coarse microstructural grains at high-energy consumption (Zhang et al , 2011).…”

Microstructure and Dry Sliding Wear of Ti-50Al Alloy and Ti-47Al-3W/Ti<SUB>2</SUB>AlC Composite Produced by Reactive Arc-Melting

“…A reactive arc-melting technique as reported elsewhere 9,17,18) was used to fabricate the Ti-50Al alloys and Ti-47Al-3W/Ti 2 AlC composites. The powders prepared are high purity elemental powders of titanium (99.5%, À350 mesh), aluminum (99.9%, À150 mesh), tungsten (99.95%, particle size; $1mm), and carbon (graphite, 99.99%, À400 mesh).…”