The Emergence for Multilamellar Ti–Al–N Solid Solution in Ti/AlN Composites Sintered at Various Temperatures

Abstract

Nowadays, a variety of coatings such as Ti–Al–N and TiN have been proposed in titanium machining, but few results on fabrication of bulk Ti/AlN composites were reported. Here, we prepared bulk Ti‐60 wt%AlN composites via vacuum hot‐press sintering at 1250°C–1450°C under an applied pressure of 30 MPa for 1 h. With sintering temperature increasing, the mechanical properties of Ti/AlN composites improved and achieved the maximum values when the sintering temperature is 1450°C. SEM detected the multilamellar grains which are confirmed as Ti–Al–N solid solution by XRD and EDS. Finally, microstructure evolution and phase transformation of Ti/AlN composites were illustrated that Al and N atoms diffuse across the grain boundary and react with Ti atoms to form TiN phase and multilamellar Ti–Al–N solid solution. This work is interesting for producing high strength and toughens metal/ceramic composites.

Synthesis and Characterization of a Nearly Single Bulk Ti2AlN MAX Phase Obtained from Ti/AlN Powder Mixture through Spark Plasma Sintering

“…Concretely, when the Al and N atoms of AlN have enough energy, they diffuse into the Ti. Then, TiN and Ti-Al compounds are formed [ 22 ], together with a variety of others Ti-Al phases such as TiAl, Ti 3 Al, Al 3 Ti and, Al 2 Ti. Finally, due to the solubility of the N atoms, TiN and TiAl react and precipitate as Ti 2 AlN [ 5 , 20 ].…”

“…There are several powder metallurgy methods to synthesize the bulk Ti 2 AlN MAX phase, starting with the combination of Ti/Al (using N 2 atmosphere), Ti/AlN or Ti/Al/TiN as raw materials, including hot isostatic pressing (HIP) [ 12 , 13 ], self-propagating high-temperature synthesis (SHS) [ 14 , 15 , 16 , 17 ], mechanical alloying (MA) and hot pressing (HP) [ 18 ], SHS and HP [ 19 ], HP [ 20 , 21 , 22 , 23 ], reaction sintering [ 24 , 25 ] and spark plasma sintering (SPS) [ 26 , 27 , 28 , 29 , 30 ]. Among them, the SPS demonstrates economic and technological advantages in the processing and formation of single phases, such as shorter soaking time, lower sintering temperatures, higher density and densification rate, improved mechanical properties, and refined grain sizes [ 31 ].…”

Study of the Influence of Sintering Atmosphere and Mechanical Activation on the Synthesis of Bulk Ti2AlN MAX Phase Obtained by Spark Plasma Sintering

“…For the production of the Ti 2 AlN MAX phase, several powder metallurgy processes have been used, such as self-propagating high-temperature synthesis (SHS) [ 11 , 12 , 13 ], microwave sintering [ 14 ], hot pressing (HP) [ 15 , 16 , 17 , 18 , 19 , 20 ], hot isostatic pressing (HIP) [ 13 , 21 , 22 ], and spark plasma sintering (SPS) [ 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. The processing approach may be used depending on starting powder mixtures such as Ti+Al (milled in a nitrogen atmosphere), Ti+AlN, TiN+AlN, Ti+TiN+AlN, Ti+Al+TiN, under vacuum, argon, or nitrogen.…”

Microstructure evolution and phase transformation of TiB2/SiC/B4C composites synthesized from Ti‐SiC‐B4C ternary system

“…Advanced ceramic matrix composites (CMCs) have attracted extensive attention due to their good mechanical properties and thermal stability such as high Young's modulus, flexural strength, Vickers hardness and durability of high temperature . Among them, SiC/B 4 C matrix composites are regarded as promising structural composites which can be applied in industry, defense and aerospace .…”

“…Advanced ceramic matrix composites (CMCs) have attracted extensive attention due to their good mechanical properties and thermal stability such as high Young's modulus, flexural strength, Vickers hardness and durability of high temperature. [1][2][3] Among them, SiC/B 4 C matrix composites are regarded as promising structural composites which can be applied in industry, defense and aerospace. 4,5 Moreover, B 4 C ceramic is typically utilized in nuclear reactors owing to its neutron absorbing capability, 6 and SiC ceramic has been an important part of Ultra high-temperature structural materials.…”