“…As it can be seen Figure 4 c–e, the crystal lattices of Co and WC are obviously incoherent and the interface is clean and free of any inclusions, defects, or disorders, which explains the complete wetting of WC by the Co-based binders with the medium-low carbon contents [ 1 , 2 ].…”
Section: Resultsmentioning
confidence: 99%
“…The interaction between Co-based binders and WC grains on early stages of liquid-phase sintering can be strongly affected by the carbon content in the binders, which was established in refs. [ 1 , 2 ]. In ref.…”
Section: Introductionmentioning
confidence: 99%
“…It was suggested in refs. [ 1 , 2 ] that this phenomenon occurs as a result of different wettability rates of WC by binders with various carbon contents. However, a mechanism explaining the different wettability rates with respect to the WC/Co interfaces on the micro-, nano-, and atomic-level is not understood.…”
Interfaces between alloys simulating binders in WC-Co cemented carbides and tungsten carbide were examined on the micro-, nano-, and atomic-scale. The precipitation of fine WC grains and η-phase occurs at the interface of the alloy with the low carbon content. The precipitation of such grains almost does not occur in the alloy with the medium-low carbon content and does not take place in the alloy with the high carbon content. The formation of Co nanoparticles in the binder alloy with the medium-low carbon content was established. Interfaces in the alloy with the medium-low carbon content characterized by complete wetting with respect to WC and with the high carbon content characterized by incomplete wetting were examined at an atomic scale. The absence of any additional phases or carbon segregations at both of the interfaces was established. Thus, the phenomenon of incomplete wetting of WC by liquid binders with high carbon contents is presumably related to special features of the Co-based binder alloys oversaturated with carbon at sintering temperatures.
“…As it can be seen Figure 4 c–e, the crystal lattices of Co and WC are obviously incoherent and the interface is clean and free of any inclusions, defects, or disorders, which explains the complete wetting of WC by the Co-based binders with the medium-low carbon contents [ 1 , 2 ].…”
Section: Resultsmentioning
confidence: 99%
“…The interaction between Co-based binders and WC grains on early stages of liquid-phase sintering can be strongly affected by the carbon content in the binders, which was established in refs. [ 1 , 2 ]. In ref.…”
Section: Introductionmentioning
confidence: 99%
“…It was suggested in refs. [ 1 , 2 ] that this phenomenon occurs as a result of different wettability rates of WC by binders with various carbon contents. However, a mechanism explaining the different wettability rates with respect to the WC/Co interfaces on the micro-, nano-, and atomic-level is not understood.…”
Interfaces between alloys simulating binders in WC-Co cemented carbides and tungsten carbide were examined on the micro-, nano-, and atomic-scale. The precipitation of fine WC grains and η-phase occurs at the interface of the alloy with the low carbon content. The precipitation of such grains almost does not occur in the alloy with the medium-low carbon content and does not take place in the alloy with the high carbon content. The formation of Co nanoparticles in the binder alloy with the medium-low carbon content was established. Interfaces in the alloy with the medium-low carbon content characterized by complete wetting with respect to WC and with the high carbon content characterized by incomplete wetting were examined at an atomic scale. The absence of any additional phases or carbon segregations at both of the interfaces was established. Thus, the phenomenon of incomplete wetting of WC by liquid binders with high carbon contents is presumably related to special features of the Co-based binder alloys oversaturated with carbon at sintering temperatures.
“…Functionally graded MLG/WC–TiC–Al 2 O 3 composites fabricated by a two-stage hot pressing sintering technique were also found to be well-suited for use as high-speed cutting tools [149]. The self-lubricating effect and superior thermal conductivity of MLG are the critical contributors to the improved tribological performance of the FGCMs. Figure 67. Functionally graded WC–Co hardmetal cutting tool insert and its microstructures in the surface layer and core region [270]. (cited image has been reproduced with due permission from the publisher).…”
Monolithic components are often insufficient when a combination of conflicting properties, or a variation in properties at different regions within a material is required. Functionally graded composite materials (FGCM) are a relatively new class of materials with a systematic variation of the composition, microstructure, and properties along one direction. The graded structure offers tailorable property combinations not achievable with monolithic composites and significant recent research has been carried out on their development. An effort has been made in this article to review the latest developments on bulk FGCMs since 2015. The different processing techniques used for their fabrication have been discussed, highlighting their advantages, limitations, and recent advancements pertaining to FGCM fabrication. Various physical, mechanical, and thermal properties of FGCMs have been treated separately, and wherever possible, summary plots combining data from various research articles have been developed. Finally, potential areas for directing future FGCM research have been identified.
“…Inspired by the structures of wheat awn and softwood branches [2], turtle rib [3], shark denticle [4], bamboo [5] and other natural structures, many scientific research teams have been trying to find an optimal method from nature to achieve higher performance requirements [6][7][8][9]. Function graded structure (FGS) is one of the design methods derived from nature, and has been widely used in various fields, such as heat dissipating [10,11], energy absorption [12][13][14][15], optoelectronic and thermoelectric [16], biomedical prosthetic device [17][18][19][20][21] machinery and equipment application [22,23].…”
：Compared with uniform structures, functionally graded lattice structures can control mechanical properties through varying structure and volume fraction. In this study, a three-period minimal surface method was used to generate functional lattice structure with linear or quadratic function (LF or QF) gradient strategy in the forming direction, and the samples were fabricated by selective laser melting (SLM) using Ti-6Al-4V metal powder. The mechanical properties, deformation behavior, and energy absorption performance of graded lattice, LF and QF I-Wrapped Package (IW-P) lattice structures were systematically investigated through experiment and finite element analysis (FEA). Based on the experiment and numerical simulation results, the LF lattice structure shows higher elastic modules and yield strength during small strain period. And the merits of performance increased layer-by-layer under large strain. Additionally, the simulation results based on Johnson-Cook and failure model show that this model can reflect structural compression deformation behavior and mechanical performance prediction. Furthermore, the elastic modulus of LF lattice structure is higher than uniform lattice structures by nearly 61.52% under the same volume fraction. Thence, the LF or QF lattice structures have better support performance under small strain and stronger energy absorption capacity under large strain with the same volume fraction compared with other lattice structures, which shows superior potential to be applied to manufacture protective devices or vibration damping devices.
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