Properties of Cf/SiC-ZrB2-TaxCy composite produced by reactive hot pressing and polymer impregnation pyrolysis (RHP/PIP)

A method is described for the production of dense aluminum matrix composites from elemental powders in one processing step by reactive hot pressing (RHP). It encompasses both the exothermic conversion of reactants to composite product and the following hot compaction of the porous composite product. The RHP method described in this paper takes into account the gas evolution accompanying the exothermic process, ensures complete conversion of reactants, and avoids adverse reactions between aluminum matrix and graphite tooling material. In situ sample temperature measurements enable proper process control, in particular the timing of the full densification step of the hot reaction product.

Download Full-text

Reaction Synthesized Boron Nitride-Containing Composites (BNCC)

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.1385 ◽

2007 ◽

Vol 280-283 ◽

pp. 1385-1390

Author(s):

Guo Jun Zhang ◽

Tatsuki Ohji ◽

Shuzo Kanzaki

Keyword(s):

Boron Nitride ◽

Hot Pressing ◽

High Performance ◽

Hexagonal Boron Nitride ◽

High Strength ◽

Reactive Sintering ◽

Boron Source ◽

Inorganic Reactions ◽

Reactive Hot Pressing

Based on the proposed inorganic reactions a series of high performance hexagonal boron nitride-containing composites (BNCC), include SiC-BN, Si3N4-SiC-BN, SiAlON-BN, AlN-BN, Al2O3-BN, AlON-BN and mullite-BN, have been prepared via reactive hot pressing or pressureless reactive sintering. Various boron-bearing components such as B, B4C, AlB2, SiB4, SiB6, B2O3 or H3BO3, 9Al2O3×2B2O3 (9A2B) and 2Al2O3×B2O3 (2AB) are used as the boron source. On the other hand, nitrogen gas or solid state nitirgen-bearing metal nitrides such as Si3N4 and AlN can be used as the nitrogen source. The in situ synthesized composites demonstrated homogeneous and isotropical microstructures with very fine (nano-sized) BN platelets or their agglomerates distributed in the matrixes. These composites showed high strength, low elasticity and improved strain tolerance. In this article the reaction design, thermodynamics, reaction mechanisms, reactive hot pressing or pressureless reactive sintering, microstructures and mechanical properties will be discussed.

Download Full-text

Microstructure and mechanical properties of Nb4AlC3 MAX phase synthesized by reactive hot pressing

Ceramics International ◽

10.1016/j.ceramint.2018.06.031 ◽

2018 ◽

Vol 44 (14) ◽

pp. 16314-16324 ◽

Cited By ~ 2

Author(s):

A. Julian-Jankowiak ◽

P. Sallot

Keyword(s):

Mechanical Properties ◽

Hot Pressing ◽

Max Phase ◽

Microstructure And Mechanical Properties ◽

Reactive Hot Pressing

Download Full-text

The effect of various Co contents on the microstructure and properties of Ti(C,N)-TiB2-Co cermets prepared in situ via reactive hot pressing

Advances in Mechanical Engineering ◽

10.1177/1687814020925716 ◽

2020 ◽

Vol 12 (5) ◽

pp. 168781402092571

Author(s):

Xianrui Zhao ◽

Ze Yu ◽

Dunwen Zuo ◽

Qintao Li ◽

Mengxian Zhang ◽

...

Keyword(s):

Fracture Toughness ◽

Relative Density ◽

Vickers Hardness ◽

Hot Pressing ◽

Hardness Test ◽

Reactive Hot Pressing ◽

Compacting Pressure ◽

Vickers Hardness Test ◽

Scanning Electron

Ti(C,N)-TiB2-Co cermets were in situ synthesized, via reactive hot pressing from the Co-Ti-C-BN system, with a Co content ranging from 6 to 22 wt%. The microstructure, relative density, hardness, and fracture toughness of the sintered compacts was investigated by light microscopy, scanning electron microscopy, ceramic densitometry, and Vickers hardness test. The investigations indicate that during hot pressing (compacting pressure = 30 MPa), when the Co content is 14–22 wt%, the metal binder is extruded. Co and Ti are included in the extrudate, breaking the original ratio and deteriorating the properties of the sintered products. As the Co content increases from 6 wt% to 12 wt%, the porosity increases, and the relative density increases from 97.2% to 99.5%. The fracture toughness increases from 6.1 to 6.8 MPa m1/2. The Vickers hardness first increases from 1897 HV10 to the maximum 1960 HV10 and then decreases slightly to 1945 HV10.

Download Full-text