New hardenable CERMETS for cutting and forming applications

The University Carlos III has developed a new metal matrix composite (MMC) constituted by a dispersion of ceramic particles of TiCN in a steel matrix. The matrix can be hardened by heat treatment, leading to a material with high hardness and toughness, and lower ceramic content and density than the commercial cutting materials. For the further development it is necessary the collaboration with manufacturers of forming and cutting tools, as well as end users of those materials

Nuevos materiales tipo CERMET tratables térmicamente para aplicaciones de corte y conformado

La UC3M ha desarrollado un nuevo material compuesto de matriz metálica (MMC) formado por partículas cerámicas de TiCN en una matriz de acero. La matriz puede ser endurecida mediante tratamiento térmico, obteniéndose un material de elevada dureza y tenacidad con menor cantidad de fase cerámica que los materiales comerciales de corte, además de presentar menor densidad que estos. Para su completo desarrollo sería necesaria la colaboración de empresas fabricantes de matricería o usuarias de materiales de corte

Study of the properties of low-cost powder metallurgy titanium alloys by 430 stainless steel addition

Titanium is a lightweight metal with an outstanding combination of properties which make it the material of choice for many different applications. Nonetheless, its employment at industrial level is not widespread due to higher production costs with respect to competitor metals like steel and aluminium. In this work the production of low-cost titanium alloys is attempted by combining the utilisation of a powder metallurgy process and cheap alloying elements (i.e. commercial 430 stainless steel powder optimised for the powder metallurgy industry). Low-cost titanium alloys are fabricated by blending elemental titanium with stainless steel. The behaviour of the powders as well as that of the sintered materials are analysed and compared to that of a master alloy addition Ti6Al4V alloy. The produced low-cost titanium alloys show comparable properties to both wrought and powder metallurgy titanium alloys and, therefore, they are proposed as an alternative to obtain structural component made out of titanium alloys.The authors want to acknowledge the financial support from the Spanish Ministry of Science through the R&D Projects MAT2012-38650-C02-01, and from Regional Government of Madrid through the ESTRUMAT (S2009/MAT-1585) projec

Molybdeno-Aluminizing of Powder Metallurgy and Wrought Ti and Ti-6Al-4Valloys by Pack Cementation process

El artículo está disponible online en la web del editor (Elsevier) desde el 23 de junio de 2016.Wear and high temperature oxidation resistance of some titanium-based alloys needs to be enhanced, and this can beeffectively accomplished by surface treatment. Molybdenizing is a surface treatment where molybdenum is introducedinto the surface of titanium alloys causing the formation of wear-resistant surface layers containing molybdenum, whilealuminizing of titanium-based alloys has been reported to improve their high temperature oxidation properties. Whereaspack cementation and other surface modification methods have been used for molybdenizing or aluminizing of wroughtand/or cast pure titanium and titanium alloys, such surface treatments have not been reported on titanium alloys producedby powder metallurgy (PM). Also a critical understanding of the process parameters for simultaneous one stepmolybdeno-aluminizing of titanium alloys by pack cementation and the predominant mechanism for this process havenot been reported. The current research work describes the surface modification of titanium and Ti-6Al-4V prepared byPM by molybdeno-aluminizing and analyzes thermodynamic aspects of the deposition process. Similar coatings are alsodeposited to wrought Ti-6Al-4V and compared. Characterization of the coatings was carried out using scanning electronmicroscopy and x-ray diffraction. For both titanium and Ti-6Al-4V, the use of a powder pack containing ammoniumchloride as activator leads to the deposition of molybdenum and aluminium into the surface but also introduces nitrogencausing the formation of a thin titanium nitride layer. In addition, various titanium aluminides and mixed titanium aluminiumnitrides are formed. The appropriate conditions for molybdeno-aluminizing as well as the phases expected to beformed were successfully determined by thermodynamic equilibrium calculations.Regional Government of Madridthrough the project S2013/MIT-2862 (MULTIMAT-CHALLENGE-CM), and by the Ministry of Economy and Competitiveness of Spain through the project MAT2012/38650-C02-0

Fabricación de aleaciones ligeras de Titanio y Aluminio por metalurgia de polvos

La UC3M desarrolla aleaciones ligeras de Titanio y Aluminio mediante técnicas pulvimetalúrgicas permitiendo adaptar las composiciones y propiedades a aplicaciones específicas. Sectores como la automoción requieren el empleo de materiales con propiedades mejoradas que aúnen resistencia mecánica, buen comportamiento al desgaste y corrosión disminuyendo el peso de los componentes fabricados a partir de los metales tradicionalmente empleados. Para su implantación es clave la colaboración de empresa

Development of new materials by high energy milling

The Group of Powder Technology (GTP) of the University Carlos III has a wide experience in the development and processing of new materials by Powder Metallurgy (PM). The mechanical alloying (MA) process, or high energy milling, allows the attainment of powders with compositions impossible to produce by other techniques, with improved properties for structural applications, where mechanical properties are the main requirement, and for applications where other specific properties are needed. The identification of the specific needs of interested industrial sectors is a critical point in this developmen

Manufacturing of Titanium and Aluminium Light alloys by powder metallurgy

The Group of Powder Technology (GTP) of the University Carlos III has a wide experience in the development and processing of new materials by Powder Metallurgy (PM). The mechanical alloying (MA) process, or high energy milling, allows the attainment of powders with compositions impossible to produce by other techniques, with improved properties for structural applications, where mechanical properties are the main requirement, and for applications where other specific properties are needed. The identification of the specific needs of interested industrial sectors is a critical point in this development

High Temperature Transformations in a Steel-TiCN Cermet

The influence of the carbon content on the microstructure, phase transformation and hardness of an iron-based cermet is studied. The cermet is constituted by a high-alloyed steel as matrix, and TiCN particles (50 vol.%) as reinforcement. The material is produced by conventional powder metallurgy techniques, that is, uniaxial pressing and sintering, and the carbon content is varied from 0 wt.% to 1 wt.%. The aim of the research is the understanding of the transformations undergone by the material with increasing C amounts when temperature is increased. For this purpose, the cermet is studied by mechanical spectroscopy (MS) and differential thermal analysis (DTA) and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and hardness measurements. The equilibrium phase diagram calculated by ThermoCalc software contributes to explain the differences found on phase transformations with respect to the C content of the cermet.The authors would like to acknowledge the financial support from the Spanish Ministry of Science and Innovation through the R&D Project MAT2009-14448-C02 and Regional Government of Madrid through the program ESTRUMAT-CM (Ref. S2009/MAT-1585)Publicad

Investigation of the factors influencing the tensile behaviour of PM Ti-3Al-2.5V alloy

Titanium, a relatively new engineering metal, has been employed principally in high demanding industries due to its high final cost and it is well known for its biocompatibility. Powder metallurgy (PM) techniques could offer the possibility to reduce the production cost without paying it in terms of mechanical properties, thanks to their intrinsic advantages. In this study the Ti-3Al-2.5V titanium alloy was produced considering two powder production routes and sintered under different temperatures in order to address their feasibility as alternative to the wrought alloy. The results indicate that PM Ti-3Al-2.5V alloys studied have comparable mechanical behaviour as their counterpart obtained by conventional metallurgy and, therefore, are potential candidates to fabricate cheaper titanium products for structural applications as well as biomedical devices. © 2014 Elsevier B.V.The authors want to acknowledge the financial support from the Spanish Ministry of Science through the R&D Projects MAT2009-14448-C02-02 and MAT2009-14547-C02-02, and from Regional Government of Madrid through the ESTRUMAT (S2009/ MAT-1585) projectPublicad

Influence of carbon content on the sinterability of an FeCr matrix cermet reinforced with TiCN

The influence of carbon content on an iron-chromium cermet composite reinforced with Ti(C,N) (50 vol.%) has been studied. A thermodynamic simulation was performed using the ThermoCalc software to calculate the phase diagram of the composite. The results were validated by a thermal study performed using differential thermal analysis (DTA), and cermet samples with C percentages between 0 and 1 wt.% added to the steel matrix were prepared using a conventional powder metallurgy process. The sintered samples were characterised by measurements of density and hardness, microstructural analysis using scanning electron microscopy (SEM), microanalyses using energy dispersive X ray spectroscopy (EDX) and X-ray diffraction (XRD). The results obtained show a significant influence of the C percentage on the solidus temperature, which influences sintering behaviour, leading to changes in the Ti(C,N) particles' shape and composition, due to changes in the stoichiometry of the Ti(C,N). This influence is reflected in the cermet microstructure and hardness. The results are discussed with reference to the DTA and thermodynamic studies.The authors would like to acknowledge the financial support of the Spanish Ministry of Science and Innovation through R&D Project MAT2009-14448-C02 and the Regional Government of Madrid through the programme ESTRUMAT-CM (Ref. S2009/MAT-1585).Publicad