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.

Development of Tool Steel Matrix Composites with High Thermal Conductivity

2018 ◽  
Vol 941 ◽  
pp. 1956-1960
Author(s):  
Gen Sasaki ◽  
Yong Bum Choi ◽  
Kenjiro Sugio ◽  
Kazuhiro Matsugi
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Ball Milling ◽  
Tool Steel ◽  
Average Diameter ◽  
Steel Matrix ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Planetary Ball Milling ◽  
Tib2 Particles

The improvement of thermal conductivity of tool steel is extremely important for order to achieve life prolongation of metal die used in die-casting. In order to improve the thermal conductivity without the degradation of mechanical properties, VGCF (vapor grown carbon fiber) and TiB2 particles added in tool steel (SKD61) and to obtain the composites. Composites was fabricated by spark plasma sintering (SPS). Before sintering, SKD61 powders with 70μm in diameter and 1.9-3.8 vol. % VGCF with 0.15-0.2μm in diameter and 10-20μm in length or 4-8 vol. % TiB2 particles with 2.62μm in average diameter was mixed by V shape type ball milling or planetary ball milling. Composites were sintered at 1273K with 50 MPa. The relative density of all composites is higher than 97%. The thermal conductivity improved from 20W/mK to 36W/mK by adding 8 vol. % TiB2 particles, and to 25W/mK by adding 1.9 vol. % VGCF. On the other hand, the tensile strength of 1.9 vol. % VGCF/ SKD61 composites prepared under the condition of V shape type ball milling has 2200MPa. Composites with addition of 4vol. % TiB2 particles with V shape type ball milling and 1.9 vol. % VGCF with planetary ball milling is almost equal to the monolithic alloy. Good mechanical properties of the composites are caused by the grain refinement or interfacial strengthening by adding dispersants. But as increasing the contents of dispersants, the aggregation of the dispersants degrade the mechanical properties.

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.

scholarly journals In-Situ Synthesis, Microstructure, and Mechanical Properties of TiB2-Reinforced Fe-Cr-Mn-Al Steel Matrix Composites Prepared by Spark Plasma Sintering

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2346
Author(s):  
Jian Liu ◽  
Min Wu ◽  
Jian Chen ◽  
Zibo Ye ◽  
Cheng Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Vickers Hardness ◽  
Volume Fraction ◽  
In Situ Synthesis ◽  
Steel Matrix ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma

In-situ synthesis, microstructure, and mechanical properties of four TiB2-Reinforced Fe-Cr-Mn-Al Steel Matrix Composites have been researched in this work. The microstructure and phases of the prepared specimens have been characterized by using scanning electron microscopy (SEM), X-ray diffraction technique, and transmission electron microscopy (TEM). The sintered specimens consisted of Fe2AlCr, CrFeB-type boride, and TiB2. The mechanical properties, such as hardness and compression strength at room temperature (RT) and at elevated temperatures (600 °C and 800 °C) have been evaluated. The compressive strength and Vickers hardness of the sintered specimens increase with the volume fraction of TiB2 in the matrix, which are all much higher than those of the ex-situ TiB2/Fe-15Cr-20Mn-8Al composites and the reported TiB2/Fe-Cr composites with the same volume fraction of TiB2. The highest Vickers hardness and compressive strength at room temperature are 1213 ± 35 HV and 3500 ± 20 MPa, respectively. As the testing temperature increases to 600 °C, or even 800 °C, these composites still show relatively high compressive strength. Precipitation strengthening of CrFeB and in-situ synthesis of TiB2 as well as nanocrystalline microstructure produced by the combination of mechanical alloying (MA) and spark plasma sintering (SPS) can account for the high Vickers hardness and compressive strength.

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 Microstructure and mechanical properties of short-carbon-fiber/Ti3SiC2 composites

2020 ◽  
Vol 9 (6) ◽  
pp. 716-725
Author(s):  
Guangqi He ◽  
Rongxiu Guo ◽  
Meishuan Li ◽  
Yang Yang ◽  
Linshan Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Carbon Fibers ◽  
Vickers Hardness ◽  
Matrix Composites ◽  
Transition Layers ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Short Carbon

AbstractShort-carbon-fibers (Csf) reinforced Ti3SiC2 matrix composites (Csf/Ti3SiC2, the Csf content was 0 vol%, 2 vol%, 5 vol%, and 10 vol%) were fabricated by spark plasma sintering (SPS) using Ti3SiC2 powders and Csf as starting materials at 1300 °C. The effects of Csf addition on the phase compositions, microstructures, and mechanical properties (including hardness, flexural strength (σf), and KIC) of Csf/Ti3SiC2 composites were investigated. The Csf, with bi-layered transition layers, i.e., TiC and SiC layers, were homogeneously distributed in the as-prepared Csf/Ti3SiC2 composites. With the increase of Csf content, the KIC of Csf/Ti3SiC2 composites increased, but the σf decreased, and the Vickers hardness decreased initially and then increased steadily when the Csf content was higher than 2 vol%. These changed performances (hardness, σf, and KIC) could be attributed to the introduction of Csf and the formation of stronger interfacial phases.

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