Fabrication of Fe-TiC Composite by High-Energy Milling and Spark-Plasma Sintering

Wen

2020

Metals

The in situ reaction method for preparing metal matrix composites has the advantages of a simple process, good combination of the reinforcing phase and matrix, etc. Based on the mechanism of forming TiC x particles via the dissolution reaction of solid carbon (C) particles in Cu-Ti melt, the kinetic models for C particle dissolution reaction were established. The kinetic models of the dissolution reaction of spherical, cylindrical, and flat C source particles in Cu-Ti melt were deduced, and the expressions of the time for the complete reaction of C source particles of different sizes were obtained. The mathematical relationship between the degree of reaction of C source and the reaction time was deduced by introducing the shape factor. By immersing a cylindrical C rod in a Cu-Ti melt and placing it in a super-gravity field for the dissolution reaction, it was found that the super-gravity field could cause the precipitated TiC x particles to aggregate toward the upper part of the sample under the action of buoyancy. Therefore, the consuming rate of the C rod was significantly accelerated. Based on the flat C source reaction kinetic model, the relationship between the floating speed of TiC x particles in the Cu-Ti melt and the centrifugal velocity (or the coefficient of super-gravity G) was derived. It was proven that, when the centrifugal velocity exceeded a critical value, the super-gravity field could completely avoid the accumulation behavior of TiC x particles on the surface of the C source, thereby speeding up the formation reaction of TiC x . The goal of this study is to better understand and evaluate the generating process of TiC x particles, thus finding possible methods to increase the reaction efficiency

“…When the in situ reaction is in a steady state, i.e., the rates of steps (1-3) are equal, then the following equation can be obtained from Equations (8), (18), (22), and (23):…”

Section: Cylindrical C Sourcementioning

confidence: 99%

“…The preparation of this composite material can be divided into two ways. The first approach is to prepare TiC x powder, and then prepare MMCs by powder metallurgy [13,[17][18][19][20], or to mix TiC x powder into a metal solution and cast it [21]. The second method is to combine the preparation of TiC x powder and the composite process.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Models for the in Situ Reaction between Cu-Ti Melt and Graphite

Wen

2020

Metals

“…Among these methods, mechanical milling (MM) proved several advantages, namely uniform distribution of ceramic particles, low cost, bonding enhancing and reactions minimizing between the reinforcement and the matrix [16][17][18][19]. Spark plasma sintering (SPS) with a fast heating rate and short sintering time is a suitable technique for consolidation amorphous, nanocomposites powders [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Electrical Property of Ex-Situ and In-Situ Copper Titanium Carbide Nanocomposites

Việt

Oanh

2020

Metals

In this study, ex-situ Cu-TiC nanocomposites of 1, 3 and 5 vol. % TiC and in-situ Cu-TiH2-C nanocomposites (corresponding to 5 vol. % TiC) were prepared using ball milling and spark plasma sintering methods. Powder mixtures were milled for 4 h at 400 rpm. As-milled Cu-TiC composite powders were consolidated under an applied pressure of 70 MPa. The phase composition, and microstructure of the composite samples were characterized by X-ray diffraction, and scanning electron microscope and transmission electron microscope techniques, respectively. With the increasing TiC content from 1 to 5 vol. %, the hardness of the ex-situ composites when sintered at 600 °C changed between 161.4 and 178.5 HV and the electrical conductivity decreased from 52.1 to 47.6% IACS. In-situ Cu-TiH2-C nanocomposite sintered at 950 °C had higher hardness and electrical conductivity than ex-situ Cu-TiC composite due to having a homogenous distribution of nano reinforcement particles and dense structure.

“…Besides, the inherent brittleness of TiC is a big issue of limiting its service life cycle . To resolve both problems, a secondary ductile metal phase such as Fe, Co, Ni, Mo, and etc was purposely introduced, among which Fe was more promising because of its excellent wettability with TiC and low cost …”

Section: Introductionmentioning

confidence: 99%

Fabrication of core‐shell structured TiC–Fe composite powders by fluidized bed chemical vapor deposition

Liu

Yang

et al. 2019

J Am Ceram Soc

Fluidized bed chemical vapor deposition (FBCVD) was an effective way of preparing the core-shell structured TiC-Fe composite powders by employing FeCl 3 as a precursor. Fully covered TiC-Fe composite powders with the controllable Fe contents were readily achievable. An excellent interfacial bonding was formed between the TiC and the deposited Fe coating. The defluidization caused by the directional growth and self-nucleation-aggregation of the deposited Fe particles was the major barrier to depositing high-Fe-content composite powders. But it could be prevented by controlling the gas partial pressure of precursor and further eliminating the directional growth mode and self-nucleation behavior of Fe atoms. The optimal deposition temperature was 600°C and the partial pressure was about 20 kPa, corresponding to the gasification temperature of 275°C. K E Y W O R D Sceramic-metal systems, chemical vapor deposition, composites, core-shell structures, sinter/sintering