Effects of SiC On the Microstructure, Densification, Hardness and Wear Performance of TiB2 Ceramic Matrix Composite Consolidated Via Spark Plasma Sintering

Author(s):  
Samson Dare Oguntuyi ◽  
Mxolisi Brendon Shongwe ◽  
Lerato Tshabalala ◽  
Oluwagbenga T. Johnson ◽  
Nicholus Malatji

Abstract Monolithic TiB2 are known to have a good combination of densification and hardness which are sometimes useful but limited in application. However, their usage in service at elevated temperatures such as in power thermal plants, cutting tools, tribological purposes (cutting tools, mechanical seals, blast nozzles, and wheel dressing tools), etc leads to catastrophic failure. Hence, the introduction of sintering additives in the TiB2 matrix has a high influence on the improvement of its sinterability, and properties (fracture toughness, wear resistance etc.,) of the resulting composite needed to meets the requirement for various industrial applications. In this study, the influence of SiC as sintering additives on the microstructure, densification, hardness and wear performance of TiB2 ceramic was observed. Hence, TiB2, TiB2-10wt%SiC and TiB2-20wt%SiC were sintered at 1850 oC for 10 minutes under 50 MPa. The impacts of SiC on the TiB2 were observed to improve the microstructure correspondingly improving densification and mechanical properties, most especially with the composites with 20wt% SiC. Combined excellent densification, hardness and fracture toughness of 99.5%, 25.5 GPa, 4.5 MPa.m1/2 were achieved respectively for TiB2-20wt%SiC. Diverse in-situ phase and microstructural alterations were detected in the sintered composites, and it was discovered that the in-situ phase of TiC serves as the contributing factor to the enhanced features of the composites. Moreover, the coefficient of friction and wear performance outcomes of the synthesized composites described a decrease in the coefficient with an enhanced wear resistance via the increasing SiC particulate, although the application of the load from 10 N-20 N increased the wear rates.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chang Liu ◽  
Zhiming Li ◽  
Wenjun Lu ◽  
Yan Bao ◽  
Wenzhen Xia ◽  
...  

AbstractWear-related energy and material loss cost over 2500 Billion Euro per year. Traditional wisdom suggests that high-strength materials reveal low wear rates, yet, their plastic deformation mechanisms also influence their wear performance. High strength and homogeneous deformation behavior, which allow accommodating plastic strain without cracking or localized brittle fracture, are crucial for developing wear-resistant metals. Here, we present an approach to achieve superior wear resistance via in-situ formation of a strong and deformable oxide nanocomposite surface during wear, by reaction of the metal surface with its oxidative environment, a principle that we refer to as ‘reactive wear protection’. We design a TiNbZr-Ag alloy that forms an amorphous-crystalline oxidic nanocomposite surface layer upon dry sliding. The strong (2.4 GPa yield strength) and deformable (homogeneous deformation to 20% strain) nanocomposite surface reduces the wear rate of the TiNbZr-Ag alloy by an order of magnitude. The reactive wear protection strategy offers a pathway for designing ultra-wear resistant alloys, where otherwise brittle oxides are turned to be strong and deformable for improving wear resistance.


2004 ◽  
Vol 69 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Aleksandra Vuckovic ◽  
Snezana Boskovic ◽  
Ljiljana Zivkovic

The objective of this work was to investigate the effect of two different sintering additives (CeO2 and Y2O3 + Al2O3), sintering time and amount of ?-Si3N4 seeds on the densification, mechanical properties and microstructure of self-reinforced Si3N4 based composites obtained by pressureless sintering. Preparation of ?-Si3N4 seeds, also obtained by a pressureless sintering procedure, is described. Samples without seeds were prepared for comparison. The results imply that self-reinforced silicon nitride based composites with densities close to the theoretical values and with fracture toughness of 9.3MPa m1/2 can be obtained using a presureless sintering procedure.


2019 ◽  
Vol 1151 ◽  
pp. 47-53
Author(s):  
Feng Ding ◽  
Shu Qin Li ◽  
Ping Ze Zhang ◽  
Dong Bo Wei ◽  
Xiao Hu Chen ◽  
...  

Based on surface protection problems of the steel part of the landing gear, wear-resisting properties of tungsten carbide-cobalt (WC-Co) particles reinforced epoxy (WRE) coatings were investigated in this paper. The curing process of WRE coating was analyzed by DSC, TG and IR. The wear performance under different rotational speed WRE coating was studied respectively. The specific wear rates of the WRE coating at 560 rpm and 840 rpm are 6.04 ×10−4mm3N−1m−1and 9.55 ×10−4mm3N−1m−1respectively, about only 60% of that of the uncoated sample. Thus, this could be summarized that WRE coating had a good wear resistance.


2006 ◽  
Vol 200 (20-21) ◽  
pp. 5738-5742 ◽  
Author(s):  
G.S. Fox-Rabinovich ◽  
B.D. Beake ◽  
J.L. Endrino ◽  
S.C. Veldhuis ◽  
R. Parkinson ◽  
...  

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 304 ◽  
Author(s):  
Hongling Qin ◽  
Runzhou Xu ◽  
Pixiang Lan ◽  
Jian Wang ◽  
Wenlong Lu

Powder Bed Fusion (PBF) is an additive manufacturing technology used to produce metal-based materials. PBF materials have a unique microstructure as a result from repeated and sharp heating/cooling cycles. Many researches have been carried out on relations between processing parameters of the PBF technology, obtained microstructures and mechanical properties. However, there are few studies on the tribological properties of PBF materials at various contact conditions. This article describes previous and recent studies related to the friction performance. This is a critical aspect if PBF materials are applied to friction pair components. This paper discusses wear rates and wear mechanisms of PBF materials under dry friction, boundary lubrication and micro-motion conditions. PBF materials have higher hardness due to fine grains. PBF materials have a higher wear resistance than traditional materials due to their solid solution strengthening. In addition, hard particles on the surface of PBF components can effectively reduce wear. The reasonable combination of process parameters can effectively improve the density of parts and thus further improve the wear resistance. This review paper summarized the wear behavior of PBF materials, the wear mechanism of metal materials from dry friction to different lubrication conditions, and the wear behavior under fretting wear. This will help to control the processing parameters and material powder composition of parts, so as to achieve the required material properties of parts and further improve the wear performance.


Author(s):  
Lehua Qi ◽  
Guangzhen Pan ◽  
Yewei Fu ◽  
Xiang Zhang ◽  
Xianghui Hou ◽  
...  

Carbon fabric reinforced phenolic composites are very attractive for use as friction materials under wet conditions due to their excellent self-lubricity, wear resistance, and high mechanical strength. However, brittle fracture of carbon fabric bundles during friction is one of the major problems that limit their application. In this work, MoS2 particles were used as additives and friction modifiers to improve the wear and friction behaviors. The composites containing different amounts of MoS2 particulates (0–20 wt%) were fabricated by impregnation technique. The influence of MoS2 on the tribological properties under oil-lubricated conditions has been studied systematically. The experimental results revealed that tribological characteristics such as coefficient of friction and wear resistance were changed significantly with the relative amount of MoS2. Addition of MoS2 within 15 wt% was found to decrease the wear rates of the composites, while 20 wt% MoS2-filled composites exhibited highest wear rate compared to other test samples. Increasing MoS2 content resulted in a rise in the wear rate of the counterparts. Wear mechanisms had been investigated by scanning electron microscope, which could support the observed wear performance.


Author(s):  
X. P. Zhu ◽  
P. C. Du ◽  
Y. Meng ◽  
M. K. Lei ◽  
D. M. Guo

Surface integrity of high performance components has a profound influence on the final performance. Therefore, surface integrity is a key point for realizing high performance manufacturing by which manufacture processes and parameters can be pre-selected according to a required functional performance of components, i.e., solving inverse problem of manufacturing, as long as correlations could be established respectively for between processes and surface integrity, and between surface integrity and performance. However, in practice it is still difficult in correlating processes to performance through surface integrity, due to the material and geometry constraints hindering achievability of a desired surface integrity during conventional manufacturing as well as the complex influence of multiple surface integrity parameters on a final performance. In this study, thermally sprayed WC-10Ni coatings onto stainless steel using high velocity oxy-fuel (HVOF) spraying process are investigated to identify the surface integrity predominantly determining the water-lubricated wear performance of coated steel, and then to correlate it to process parameters. The controllable surface integrity facilitates identifying responsible surface integrity parameters for a required high performance, and subsequently deriving necessary process parameters for achieving the desired responsible surface integrity. Specifically, HVOF process parameters are adjusted by changing the oxygen-to-fuel (O/F) ratio to control thermal and mechanical processing loads, i.e. temperature of heated in-flight spraying powders and impact velocity of the molten splats onto stainless steel to form the coatings. Surface features including porosity and phase structure, and surface characteristics including hardness, elastic modulus, and fracture toughness were studied with respect to the wear performance. The porosity and WC phase composition of coatings are identified responsible for the wear performance, as two essential surface integrity parameters that in turn greatly affect the surface characteristics including coating hardness, elastic modulus and fracture toughness. Consequently, the process parameter O/F is feasibly correlated to wear resistance through the responsible surface integrity parameters, as elucidating the coating formation mechanism of influence of particle velocity and temperature on the coating porosity and WC decomposition.


2006 ◽  
Vol 315-316 ◽  
pp. 94-97 ◽  
Author(s):  
Xue Feng Yang ◽  
Jian Xin Deng ◽  
Jun Zhou ◽  
S.Q. Yao ◽  
C. Li

Three ceramic composite were prepared by hot pressing sintering. The friction and wear behaviors of the composite were experimented at the high speed wear and tear test machine. Results show that the three ceramic composite have strong fracture toughness and flexure strength. The wear mechanisms of three ceramic composite are mainly brittleness peel off and furrow. Al2O3/(W, Ti)C and Al2O3/SiCw ceramic composite have great capabilities in wear resistance; they are excellent materials of cutting tools and dies.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhu Weixin ◽  
Kong Dejun

Abstract NiMo-5%TiC, NiMo-15%TiC, and NiMo-25%TiC coatings were prepared on GCr15 steel by laser cladding (LC). The microstructure and the phases of the obtained coatings were analyzed using ultra-depth-of-field microscopy (UDFM) and X-ray diffraction (XRD), respectively. A ball-on-disk wear test was used to analyze the friction-wear performance of the substrate and the NiMo-TiC coatings under grease-lubrication condition. The results show that the grain shape of NiMo-TiC coatings is dendritic. The wear resistance of NiMo-TiC coatings is improved by the addition of TiC, and the depths of the worn tracks on the substrate and on the NiMo-5%TiC, NiMo-15%TiC, and NiMo-25%TiC coatings are 4.183 μm, 2.164 μm, 1.882 μm, and 1.246 μm, respectively, and the corresponding wear rates are 72.25 μm3/s/N, 32.00 μm3/s/N, 18.10 μm3/s/N, and 7.99 μm3/s/N, respectively; this shows that the NiMo-25%TiC coating has the highest wear resistance among the three kinds of coatings. The wear mechanism of NiMo-TiC coatings is abrasive wear, and the addition of TiC plays a role in resisting wear during the friction process.


Author(s):  
Yin Zhou ◽  
Shuqi Wang ◽  
Wei Chen ◽  
Wei Jiang ◽  
Lan Wang ◽  
...  

The effect of an oxide coating and a tribo-oxide layer on dry sliding wear of Ti–6Al–4V alloy was comparatively studied. The oxide coating was prepared on Ti–6Al–4V alloy by a thermal oxidation/diffusion process; the tribo-layer was an in situ produced mechanically mixed layer during dry sliding. The oxide coating markedly improved the wear performance of Ti–6Al–4V alloy at room and elevated temperatures. Tribo-layers were classified into three types: no-oxide tribo-layer, porous, and dense tribo-oxide layers. Both porous and dense tribo-oxide layer presented protective function, thus significantly improving wear performance of Ti–6Al–4V alloy. However, no other than dense tribo-oxide layer was qualified to be comparable to the oxide coating, which almost possessed the same wear-reduced function as the oxide coating. Even when the oxide coating was severely delaminated, the tribo-oxide layer would replace the oxide coating and took effect to protect from wear.


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