Combustion synthesis of NiAl matrix composite powder reinforced by TiB2 and TiN particulates from Ni–Al–Ti–BN reaction system

• A Novel NiAl matrix composite powder with 0–40 wt.% (TiB2–TiN) was synthesized.
• Composite powders were fabricated by thermal explosion reaction of Ni–Al–Ti–BN system.
• Microhardness of compounds noticeably increased with raising (TiB2–TiN) content.
• The synthesized composite powders are good precursor for thermal spray applications.

Combustion synthesis in thermal explosion mode was used for synthesis of a novel NiAl matrix composite powder reinforced with 0–40 wt.% (TiB2–TiN). The starting materials were Ni, Al, Ti and hexagonal boron nitride (h-BN) powders. For all compositions, final products contained only the NiAl, TiN and TiB2 phases without any intermediate or non-stoichiometric phases. The distribution of ceramic particulates in NiAl matrix was improved by raising (TiB2–TiN) content. The microhardness of samples noticeably increased with raising (TiB2–TiN) content from 374 ± 15 HV0.1 for NiAl to 909 ± 79 HV0.1 for NiAl with 40 wt.% (TiB2–TiN). Due to the high hardness of synthesized compounds and formation of reinforcements with proper size and relatively homogenous distribution, the synthesized composite powders can be considered as good precursor for thermal spray applications.