Influence of Carbon Reinforcements on the Mechanical Properties of Ti Composites via Powder Metallurgy and Hot Extrusion

2013 ◽  
Vol 750 ◽  
pp. 40-43 ◽  
Author(s):  
Shu Feng Li ◽  
Bin Sun ◽  
Katsuyoshi Kondoh ◽  
Takanori Mimoto ◽  
Hisashi Imai
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Carbon Nanofiber ◽  
Hot Extrusion ◽  
Strengthening Mechanism ◽  
Matrix Composites ◽  
Solid Solution Strengthening ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Solution Strengthening

Ti metal matrix composites (Ti–MMCs) reinforced by vapor grown carbon nanofiber (VGCF) and graphite particle (Gr) were prepared via powder metallurgy and hot extrusion. Ti with 0~0.4wt% VGCF/Gr mixture powders were consolidated by using spark plasma sintering (SPS) at 800 °C. Hot extrusion was then performed at 1000 °C with an extrusion ratio of 37:1. Microstructures and mechanical properties of the as-extruded Ti composites were investigated. Tensile strength of Ti–VGCF/Gr composites was steadily augmented when additions of VGCF/Gr were increased from 0.1 to 0.4 wt%. YS and UTS were increased 40.2% and 11.4% for Ti–0.4wt%VGCF as compared to pure Ti, while those values were 30.5% and 2.1% for Ti–0.4wt%Gr. The strengthening mechanism including grain refinement, carbon solid solution strengthening and dispersion hardening of TiC/carbon was discussed in detail.

In Situ Decomposition of Silicon Nitride Particles in Titanium Composite and its Mechanical Properties

2017 ◽  
Vol 737 ◽  
pp. 38-43
Author(s):  
Hisashi Imai ◽  
Hiroyasu Yamabe ◽  
Katsuyoshi Kondoh ◽  
Junko Umeda ◽  
Anak Khantachawana
Keyword(s):  
Mechanical Properties ◽  
Silicon Nitride ◽  
Solid Phase ◽  
High Strength ◽  
Solid Solution Strengthening ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Solution Strengthening ◽  
Ti Powder

Dependence of the mechanical properties of PM extruded titanium with the silicon nitride (Si3N4) on solid phase decomposition of Si3N4 was investigated. Si3N4 particles within Ti composite powder were decomposed during spark plasma sintering at 1223 K with 30 MPa pressure for 3.6 ks; and then, decomposition by-products of nitrogen and silicon atoms were defused into titanium matrix. The extruded Ti-1.0 mass% Si3N4 composite showed ultimate tensile strength (UTS) of 1139 MPa, and yield stress (0.2%YS) of 1065 MPa. UTS and 0.2%YS of P/M extruded Ti-1.0 mass% Si3N4 composite were 2 and 2.5 times compared to extruded pure Ti powder material, respectively. It was considered that the solid solution strengthening of both nitrogen and silicon originated from Si3N4 caused the high strength of PM extruded Ti-1.0 mass% Si3N4 composite.

Microstructural and Mechanical Properties of Titanium Matrix Composites Reinforced with Nano Carbon Materials via Powder Metallurgy Process

2009 ◽  
Vol 618-619 ◽  
pp. 495-499 ◽  
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Junko Umeda ◽  
Hisashi Imai ◽  
Bunshi Fugetsu
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Pure Titanium ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Matrix Composites ◽  
Dispersion Strengthening ◽  
Titanium Matrix ◽  
Wet Process ◽  
Plasma Sintering

Powder metallurgy (P/M) titanium matrix composite (TMC) reinforced with multi-wall carbon nanotube (MWCNT) was prepared by spark plasma sintering (SPS) and hot extrusion process, where the powder surface was coated by un-bundled CNTs via wet process. The microstructure and mechanical properties of P/M pure titanium and reinforced with CNTs were evaluated. The distribution of CNTs and in-situ formed titanium carbide (TiC) compounds during sintering was investigated by optical and scanning electron microscopy (SEM) equipped with EDS analyser. The mechanical properties of TMC were significantly improved by adding a small amount of CNTs. For example, when employing the pure titanium composite powder coated with CNTs of 0.35 mass%, the increase of tensile strength and yield stress of the extruded TMC was 157 MPa and 169 MPa, respectively, compared to those of extruded titanium materials with no CNT additive. Fractured surfaces of specimens were analysed by SEM, and the uniform distribution of CNTs and TiC particles, being effective for the dispersion strengthening, at the surface of the TMC were obviously observed.

Development of Tool Steel Matrix Composites With High Thermal Conductivity

2020 ◽  
Author(s):  
Gen Sasaki ◽  
Yongbum Choi ◽  
Kenjiro Sugio
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tool Steel ◽  
Carbon Nanofiber ◽  
Average Diameter ◽  
Steel Matrix ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Tib2 Particles

Abstract The improvement of thermal conductivity of tool steel is a very important problem to achieve life prolongation of a metal die used in press forming and die-casting and obtain large size or complex shape products with good mechanical properties. To improve the thermal conductivity without the degradation of mechanical properties, some kind of dispersants were added into tool steel 40CrMoV5 in ISO standard. 0.5–1.0 vol. % carbon nanofiber, 4–8 vol. % TiB2 particles with 2.62 micrometer in average diameter and 8 vol. % Cu particles was added in tool steel. Dense composites were fabricated by spark plasma sintering by controlling sintering temperature and time. The thermal conductivity was improved by adding all dispersant. Strength of carbon nanofiber / steel composites increased by adding 0.5 vol. % fiber, but decreased by adding 1.0 vol. % because of aggregation of carbon fiber. Some chemical reaction occurred in TiB2 particles/ steel composites, and the elongation improved because of the boron element in the interface. Cu /steel composites keep good strength compared with monolithic tool steel and the thermal conductivity increased dramatically as increasing Cu contents.

scholarly journals Physical, mechanical properties and wear resistance of iron-base matrix materials for sintered diamond tools fabricated by HP and SPS

Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 846-849
Author(s):  
Elżbieta Bączek
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Metal Matrix ◽  
Physical And Mechanical Properties ◽  
Full Density ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Base Matrix ◽  
Spark Plasma ◽  
Sintered Diamond

Metal matrix composites were prepared by hot pressing (HP) and spark plasma sintering (SPS) techniques. Ball-milled ironbase powders were consolidated to near full density by these methods at 900°C. The physical and mechanical properties of the resulting composites were investigated. The specimens were tested for resistance to both 3-body and 2-body abrasion. The composites obtained by HP method (at 900°C/35 MPa) had higher density, hardness and resistance to abrasion than those obtained by SPS method.

scholarly journals Powder Metallurgy Processing and Mechanical Properties of Controlled Ti-24Nb-4Zr-8Sn Heterogeneous Microstructures

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1626
Author(s):  
Benoît Fer ◽  
David Tingaud ◽  
Azziz Hocini ◽  
Yulin Hao ◽  
Eric Leroy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Ball Milling ◽  
Processing Route ◽  
Fine Grain ◽  
Plasma Sintering ◽  
3D Network ◽  
Spark Plasma ◽  
Powder Particles ◽  
Heterogeneous Microstructures

This paper gives some insights into the fabrication process of a heterogeneous structured β-metastable type Ti-24Nb-4Zr-8Sn alloy, and the associated mechanical properties optimization of this biocompatible and low elastic modulus material. The powder metallurgy processing route includes both low energy mechanical ball milling (BM) of spherical and pre-alloyed powder particles and their densification by Spark Plasma Sintering (SPS). It results in a heterogeneous microstructure which is composed of a homogeneous 3D network of β coarse grain regions called “core” and α/β dual phase ultra-fine grain regions called “shell.” However, it is possible to significantly modify the microstructural features of the alloy—including α phase and shell volume fractions—by playing with the main fabrication parameters. A focus on the role of the ball milling time is first presented and discussed. Then, the mechanical behavior via shear tests performed on selected microstructures is described and discussed in relation to the microstructure and the probable underlying deformation mechanism(s).

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