Olivier Martin

Bio: Olivier Martin is an academic researcher from Mecachrome (France). The author has contributed to research in topics: Rietveld refinement & Turbine blade. The author has an hindex of 4, co-authored 15 publications receiving 83 citations.

Microstructure and mechanical properties of an Al–TiC metal matrix composite obtained by reactive synthesis

Abstract: A metal matrix composite has been obtained by a novel synthesis route, reacting Al 3 Ti and graphite at 1000 °C for about 1 min after ball-milling and compaction. The resulting composite is made of an aluminium matrix reinforced by nanometer sized TiC particles (average diameter 70 nm). The average TiC/Al ratio is 34.6 wt.% (22.3 vol.%). The microstructure consists of an intimate mixture of two domains, an unreinforced domain made of the Al solid solution with a low TiC reinforcement content, and a reinforced domain. This composite exhibits uncommon mechanical properties with regard to previous micrometer sized Al–TiC composites and to its high reinforcement volume fraction, with a Young’s modulus of ∼110 GPa, an ultimate tensile strength of about 500 MPa and a maximum elongation of 6%.

Transformation Kinetics and Resulting Microstructure in MMC Reinforced with TiC Particles

Abstract: The phase transformation kinetics on cooling and resulting microstructures of steel-based matrix composites (MMC) reinforced with TiC particles by powder metallurgy were studied. In addition, the phase transformation kinetics of the MMC were compared to those of the same steel without TiC and consolidated in the same conditions. The presence of TiC particles strongly favors the diffusive transformations in the steel matrix of the MMC. Different complementary techniques (XRD, SEM, TEM/EDX, atom probe tomography, in situ synchrotron XRD) were performed to analyze the chemical reactivity between TiC particles and the steel powders occurring during consolidation process and further heat treatments. Composition changes in the TiC as well as in the matrix were characterized. The chemical composition after treatment in the TiC particles tends toward the thermodynamic calculations with ThermoCalc. The effect of changes in chemical composition and the role of TiC particles acting as new favorable nucleation sites are discussed in regards to the obtained results.

Method and Device for Manufacturing Turbine Blades

Abstract: The present invention relates to a method and device for manufacturing turbine blades (5; 7; 28; 33) made of a metal alloy. Starting with an aluminium and titanium alloy bar (10; 34) having a simple and/or axisymmetric shape, at least two mutually interlocking blanks (2; 3; 4; 8; 11) are produced in the bar (10; 34) by waterjet cutting (16), and then each one of said blanks (2; 3; 4; 8; 11) thus obtained is machined separately in order to obtain the blades (5; 7; 28; 33) having a final profile.

Device and method for cutting parts consisting of a metal or composite material and parts produced with such a method

Abstract: The invention relates to a device, a method and an assembly of parts produced by cutting in a block B of metal or composite material, following a determined trajectory. The device comprises a guide (3) forming said trajectory and a support (chain 9) mounted in the guide in a sliding manner, comprising a lateral blank (23) provided with at least one cutting plate (24) comprising a protruding cutting edge (25) arranged so as to carry out the cutting in a normal direction (26) in relation to the blank.

Dispositif et procede de decoupe de pieces en materiau metallique ou composite et pieces obtenues avec un tel procede

Abstract: La presente invention concerne un dispositif, un procede et un ensemble de pieces obtenues par decoupe dans un bloc B en materiau metallique ou composite suivant une trajectoire determinee. Le dispositif comprend un guide (3) formant ladite trajectoire et un support (chaine 9) monte coulissant dans le guide, comportant un flan lateral (23) muni d'au moins une plaquette (24) de coupe comprenant une arete (25) de coupe en saillie agencee pour effectuer la decoupe dans une direction normale (26) par rapport au flan.

Ultra-High Temperature Materials III: Refractory Carbides II (Ti and V Carbides)

Abstract: The series of books represents a thorough treatment of ultra-high temperature materials with melting (sublimation or decomposition) points around or over 2500 °C. In the third volume are included physical (structural, thermal, electromagnetic, optical, mechanical, nuclear) and chemical (more than 1100 binary, ternary and multi-component systems, including those used for materials design, data on solid-state diffusion, wettability, interaction with chemicals, gases and aqueous solutions) properties of titanium monocarbide TiC1–x, vanadium monocarbide VC1–x and related 2D-molecular (graphene-like) carbide MXenes, discovered and developed only in the last decade. TiC1–x and VC1–x are also widely applied in the general technological and engineering practice in a wide range of temperatures as parts of highly hard materials (alloys) and special steels. This book will be of interest to researchers, engineers, postgraduate, graduate and undergraduate students alike. For the named materials, readers/users are provided with the full qualitative and quantitative assessment, which is based on the latest updates in the field of fundamental physics, chemistry, nanotechnology, materials science, design and engineering.

Interfacial microstructure of graphite flake reinforced aluminum matrix composites fabricated via hot pressing

Abstract: The microstructure of graphite flake (GF) reinforced aluminum (Al) matrix (Al–GF) composites was observed in detail. Due to thermal mismatch between Al and GF, an inner structure of GF was damaged in proximity to the Al/GF interface, while the unique bridging of the sticky graphite sheets barely connected the Al matrix and GF. This result suggests that the GF interlaminar strength is weaker than the Al/GF interfacial strength; the GF interlaminar strength is thus the dominant determinant of the thermomechanical and mechanical properties of the Al–GF composite. Whereas the thermal conductivity of the Al–GF composite was consistent with that theoretically predicted, the outstanding thermal expansion coefficient (TEC) of the graphite was not reflected in the produced Al–GF composites. The damaged inner structure of GF in proximity to the Al/GF interface contributes to heat transfer but does not bear the load resulting from thermal stress.

Evaluation of Microstructure and Mechanical Properties of Al-TiC Metal Matrix Composite Prepared by Conventional, Microwave and Spark Plasma Sintering Methods.

Abstract: In this research, the mechanical properties and microstructure of Al-15 wt % TiC composite samples prepared by spark plasma, microwave, and conventional sintering were investigated. The sintering process was performed by the speak plasma sintering (SPS) technique, microwave and conventional furnaces at 400 °C, 600 °C, and 700 °C, respectively. The results showed that sintered samples by SPS have the highest relative density (99% of theoretical density), bending strength (291 ± 12 MPa), and hardness (253 ± 23 HV). The X-ray diffraction (XRD) investigations showed the formation of TiO2 from the surface layer decomposition of TiC particles. Scanning electron microscopy (SEM) micrographs demonstrated uniform distribution of reinforcement particles in all sintered samples. The SEM/EDS analysis revealed the formation of TiO2 around the porous TiC particles.

Advanced production routes for metal matrix composites

Abstract: The use of metal matrix composites (MMCs) in a variety of products is significantly increasing with time due to the fact that their properties can be tailored and designed to suit specific applications. However, the future usage of MMC products is very much dependent on their beneficial aspects and hence it is critical to ensure in a robust repeatable manner the superior physical property advantages compared to conventional unreinforced monolithic metal counterparts. Although numerous routes are available for production of MMC products, each of them has their own advantages and disadvantages. This article provides an overview of advanced production routes for MMCs. The discussion also highlights challenges and presents a future prospectus for MMCs. Powder metallurgy and casting routes are still extensively used for production of MMCs. Aluminum alloys are today the most commonly used matrix materials in MMC products. Carbides (eg, SiC, TiC, and B4C), carbon allotropes (eg, CNTs and graphene), and alumina (Al2O3) are currently the most used reinforcement materials. Nevertheless, the use of nano and of hybrid reinforcements are seeing increased usage in niche applications. Additive manufacturing (AM) is discussed as a novel production route for MMC products. This process represents a promising method for the production of MMC products.