Microstructure, Mechanical Properties and Wear Resistance of WC/Co Nanocomposites

1996 ◽  
Vol 457 ◽  
Author(s):  
Kang Jia ◽  
Traugott E. Fischer
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Adhesive Wear ◽  
Liquid Phase Sintering ◽  
Binder Phase ◽  
Slow Cooling ◽  
Diamond Indenter ◽  
Grain Fragmentation ◽  
Spray Conversion

ABSTRACTThe microstructure, mechanical properties, abrasion and wear resistance of WC-Co nanocomposites synthesized by the spray conversion technique by McCandlish, Kear and Kim have been investigated. The binder phase of WC-Co nanocomposites is enriched in W and C, compared to conventional cermets. Small amorphous regions exist in the binder despite the slow cooling after liquid phase sintering. Few dislocations are found in the WC grains. The increased WC content and the amorphous regions modify (i.e. strengthen) the binder phase of the composites. Vickers indentation measurements show a hardness of the nanocomposites reaching 2310 kg/mm2. While the toughness of conventional cermets decreases with increasing hardness, the toughness does not decrease further as the WC grain size decreases from 0.7 to 0.07 μm. but remains constant at 8 MPam1/2. Scratches caused by a diamond indenter are small, commensurate with their hardness. These scratches are ductile, devoid of the grain fracture that is observed with conventional materials. The abrasions resistance of nanocomposites is about double that of conventional materials, although their hardness is larger by 23% only. This is due to the lack of WC grain fragmentation and removal which takes place in conventional cermets. Sliding wear resistance of WC/Co is proportional to their hardness; no additional benefit of nanostructure is obtained. This results from the very small size of adhesive wear events in even large WC grains.

scholarly journals Effects of Boron Addition on the Microstructure and Mechanical Properties of (Ti,Ta)(C,N)-Co Based Cermets

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 787
Author(s):  
Ernesto Chicardi ◽  
Francisco José Gotor Martínez
Keyword(s):  
Mechanical Properties ◽  
Liquid Phase ◽  
Intermetallic Compound ◽  
Solid Solutions ◽  
General Trend ◽  
Liquid Phase Sintering ◽  
Binder Phase ◽  
Boron Addition ◽  
Sintering Additive ◽  
Microstructure And Mechanical Properties

In this work, a titanium–tantalum carbonitride based cermet, with cobalt as the binder phase and boron as a sintering additive, was developed by a mechanically induced self-sustaining reaction process using two different methodologies. The boron additive was added to prevent the formation of brittle intermetallic compounds generally formed during the liquid phase sintering step due to the excessive ceramic dissolution into the molten binder phase. A systematic study was carried out to understand the effects of boron addition on the nature of the phases, microstructure, and mechanical properties of cermets. With the boron addition, the formation of two different boride solid solutions, i.e., (Ti,Ta)B2 and (Ti,Ta)3B4, was observed. Moreover, the nature of the binder was also modified, from the (Ti,Ta)Co2 brittle intermetallic compound (for cermets without boron addition) to ductile and tough (Ti,Ta)Co3 and α-Co phases (for cermets with boron addition). These modifications caused, as a general trend, the increase of hardness and toughness in cermets.

Improving the dry sliding-wear resistance of B4C ceramics by transient liquid-phase sintering

2020 ◽  
Vol 40 (15) ◽  
pp. 5286-5292 ◽  
Author(s):  
Cristina Ojalvo ◽  
Estíbaliz Sánchez-González ◽  
Fernando Guiberteau ◽  
Oscar Borrero-López ◽  
Angel L. Ortiz
Keyword(s):  
Wear Resistance ◽  
Liquid Phase ◽  
Sliding Wear ◽  
Transient Liquid Phase ◽  
Liquid Phase Sintering ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Transient Liquid Phase Sintering

A Comparison of the Tribo-Mechanical Properties of a Wear Resistant Cobalt-Based Alloy Produced by Different Manufacturing Processes

2007 ◽  
Vol 129 (3) ◽  
pp. 586-594 ◽  
Author(s):  
H. Yu ◽  
R. Ahmed ◽  
H. de Villiers Lovelock
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Wear Mechanisms ◽  
Sliding Wear ◽  
Mechanical Performance ◽  
Cast Alloy ◽  
Processing Route ◽  
Structure Property ◽  
Wear Resistant ◽  
The Impact

This paper aims to compare the tribo-mechanical properties and structure–property relationships of a wear resistant cobalt-based alloy produced via two different manufacturing routes, namely sand casting and powder consolidation by hot isostatic pressing (HIPing). The alloy had a nominal wt % composition of Co–33Cr–17.5W–2.5C, which is similar to the composition of commercially available Stellite 20 alloy. The high tungsten and carbon contents provide resistance to severe abrasive and sliding wear. However, the coarse carbide structure of the cast alloy also gives rise to brittleness. Hence this research was conducted to comprehend if the carbide refinement and corresponding changes in the microstructure, caused by changing the processing route to HIPing, could provide additional merits in the tribo-mechanical performance of this alloy. The HIPed alloy possessed a much finer microstructure than the cast alloy. Both alloys had similar hardness, but the impact resistance of the HIPed alloy was an order of magnitude higher than the cast counterpart. Despite similar abrasive and sliding wear resistance of both alloys, their main wear mechanisms were different due to their different carbide morphologies. Brittle fracture of the carbides and ploughing of the matrix were the main wear mechanisms for the cast alloy, whereas ploughing and carbide pullout were the dominant wear mechanisms for the HIPed alloy. The HIPed alloy showed significant improvement in contact fatigue performance, indicating its superior impact and fatigue resistance without compromising the hardness and sliding∕abrasive wear resistance, which makes it suitable for relatively higher stress applications.

scholarly journals Mechanical Properties and Sliding Wear Resistance of Suspension Plasma Sprayed YSZ Coatings

2020 ◽  
Vol 14 (4) ◽  
pp. 307-314
Author(s):  
Leszek Łatka ◽  
Mirosław Szala ◽  
Wojciech Macek ◽  
Ricardo Branco
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Plasma Sprayed

scholarly journals Mechanical Properties and Sliding-impact Wear Resistance of Self-adhesive Resin Cements

2016 ◽  
Vol 41 (3) ◽  
pp. E83-E92 ◽  
Author(s):  
T Furuichi ◽  
T Takamizawa ◽  
A Tsujimoto ◽  
M Miyazaki ◽  
WW Barkmeier ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Sliding Wear ◽  
Resin Cement ◽  
The Self ◽  
Volume Loss ◽  
Resin Cements ◽  
Adhesive Resin

SUMMARY The present study determined the mechanical properties and impact-sliding wear characteristics of self-adhesive resin cements. Five self-adhesive resin cements were used: G-CEM LinkAce, BeautiCem SA, Maxcem Elite, Clearfil SA Automix, and RelyX Unicem 2. Clearfil Esthetic Cement was employed as a control material. Six specimens for each resin cement were used to determine flexural strength, elastic modulus, and resilience according to ISO specification #4049. Ten specimens for each resin cement were used to determine the wear characteristics using an impact-sliding wear testing apparatus. Wear was generated using a stainless-steel ball bearing mounted inside a collet assembly. The maximum facet depth and volume loss were determined using a noncontact profilometer in combination with confocal laser scanning microscopy. Data were evaluated using analysis of variance followed by the Tukey honestly significantly different test (α=0.05). The flexural strength of the resin cements ranged from 68.4 to 144.2 MPa; the elastic modulus ranged from 4.4 to 10.6 GPa; and the resilience ranged from 4.5 to 12.0 MJ/m3. The results for the maximum facet depth ranged from 25.2 to 235.9 μm, and volume loss ranged from 0.0107 to 0.5258 mm3. The flexural properties and wear resistance were found to vary depending upon the self-adhesive resin cement tested. The self-adhesive cements tended to have lower mechanical properties than the conventional resin cement. All self-adhesive resin cements, apart from G-CEM LinkAce, demonstrated significantly poorer wear resistance than did the conventional resin cement.

scholarly journals Microstructure and Properties of AA6061/SiCp Composites Sintered under Ultra High-Pressure

2020 ◽  
Vol 10 (20) ◽  
pp. 7363
Author(s):  
Lei Xu ◽  
Erkuo Yang ◽  
Yasong Wang ◽  
Changyun Li ◽  
Zhiru Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Wear Property ◽  
Ultra High Pressure ◽  
High Pressure Sintering

Ultra high-pressure sintering (UHPS) was used to prepare AA6061/SiCp composites with different contents and the effect of sintering temperatures on microstructure and mechanical properties was investigated in this study. The results showed that a uniform distribution of nano-SiC particles (N-SiCp) is obtained by the UHPS method. With the increase in N-SiCp contents, the higher hardness and better wear resistance could be inspected. The interfacial reactions and Al4C3 phase appeared above 550 °C. The relative density of composites first increased and then decreased; with the temperature raising it reached 99.58% at 600 °C. The hardness and wear property showed the same trend with the hardness reaching 52 HRA and wear rate being 1.0 × 10−6 g/m at 600 °C. Besides, the wear mechanism of the composites is mainly composed of abrasive wear and adhesive wear.

Wear and Mechanical Properties of Fe-28Al and Fe-28Al-10Ti Alloys

2011 ◽  
Vol 295-297 ◽  
pp. 256-259
Author(s):  
Jing Li ◽  
Jin Shan Zhao
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Plastic Deformation ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Bulk Material ◽  
Wear Test ◽  
Long Distance ◽  
Wear Performance ◽  
Worn Surface

Fe-28Al and Fe-28Al-10Ti alloys were prepared by mechanical alloying and hot pressed sintering. The mechanical properties and wear resistance were studied. The results show that Fe-28Al bulk material is mainly characterized by the low ordered B2 Fe3Al structure with some dispersed Al2O3 particles. The mechanical properties such as the hardness and strength of Fe-28Al-10Ti are significantly improved compared with Fe-28Al, which is attributed to the grain refinement and solid solution reinforcing with the addition of Ti element. The fracture mode is mainly the intergranular fracture. Fe-28Al-10Ti exhibits more excellent wear resistance than Fe-28Al, especially after long distance sliding wear test. There is difference in wear mechanisms of Fe-28Al and Fe-28Al-10Ti alloys. Under the load of 100N, there is obvious plastic deformation on the worn surface of Fe-28Al. Micro-crack and layer splitting occur on the surface of Fe-28Al. The main wear performance of Fe-28Al-10Ti is particle abrasion, the characteristics of which are micro cutting and micro furrows.

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