Structural and Mechanical Properties of Predicted Vacancy Ordered Tantalum Carbide Phases

This paper deals with the optimalization of tempering temperature of 9CrNB steel in Železiarne Podbrezová Steelworks, where hot-rolled tubes were produced with dimensions of 88.9 x 12.51 mm. Austenitising at 1070°C/12m/hr was carried out after rolling, and samples were subsequently tempered at 790°C, 760°C and 720°C/4m/hr. The results of testing the mechanical properties show that only tempering at 790°C fulfilled all of the mechanical properties requirements (Rp0,2, Rm, A5, HBW, KV2). The mechanical properties of grade P92 were used for comparison with 9CrNB mechanical properties, according to the relevant standard of STN EN 10216-2+A2. Yield strength requirements (Rp0,2) were also fulfilled in the temperature range from 100 to 600 °C. Microstructural analysis showed that tempering at 720°C, and also at 760°C does not lead to the complete tempering of martensite microstructure. We observed segregation of secondary phases at the grain boundary, but cementite films between individual laths did not coagulate to form carbide phases. By tempering at 790°C the intensity of formation of carbide phases, coagulation and growth of carbide phases is very high and leads to disintegration of laths. Despite satisfactory results, theoretical studies with respect to the selected chemical composition of 9CrNB steel show that to achieve sufficient dissolution of carbide or nitride phases (especially BN), it is necessary to use high temperature austenitization up to about 1200°C, followed by tempering below Ac1.

Download Full-text

The Effect of Incorporating Ceramic Particles with Different Morphologies on the Microstructure, Mechanical and Tribological Behavior of Hybrid TaC_ BN/AA2024 Nanocomposites

Coatings ◽

10.3390/coatings11121560 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1560

Author(s):

Emad Ismat Ghandourah ◽

Essam B. Moustafa ◽

Hossameldin Hussein ◽

Ahmed O. Mosleh

Keyword(s):

Mechanical Properties ◽

Wear Resistance ◽

Base Alloy ◽

Tantalum Carbide ◽

Heavy Particles ◽

Friction Stir ◽

Surface Composites ◽

Mechanical Durability ◽

Research Challenge ◽

Aluminum Alloy Surface

Improving the mechanical durability and wear resistance of aluminum alloys is a research challenge that can be solved by their reinforcement with ceramics. This article is concerned with the improvement of the mechanical properties and wear resistance of the AA2024 aluminum alloy surface. Surface composites were prepared by incorporating a hybrid of heavy particles (tantalum carbide (TaC), light nanoparticles, and boron nitride (BN)) into the AA2024 alloy using the friction stir process (FSP) approach. Three pattern holes were milled in the base metal to produce the composites with different volume fractions of the reinforcements. The effects of the FSP and the reinforcements on the microstructure, mechanical properties, and wear resistance are investigated. In addition to the FSP, the reinforced particles contributed to greater grain refinement. The rolled elongated grains became equiaxed ultrafine grains reaching 6 ± 1 µm. The refinement and acceptable distribution in the reinforcements significantly improved the hardness and wear resistance of the produced composites. Overall, the hardness was increased by 60% and the wear resistance increased by 40 times compared to the base alloy.

Download Full-text

The Effects of HIP, Solution Heat Treatment and Aging Treatments on the Microstructure and Mechanical Properties of Sintering Cobalt-Based Alloys Strengthened with Tantalum Carbide Additives

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.m2014066 ◽

2014 ◽

Vol 55 (11) ◽

pp. 1755-1761 ◽

Cited By ~ 4

Author(s):

Shih-Hsien Chang ◽

Chien-Chung Chen

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Solution Heat Treatment ◽

Tantalum Carbide ◽

Microstructure And Mechanical Properties

Download Full-text

Effect of SiC Nanowhisker on the Microstructure and Mechanical Properties of WC-Ni Cemented Carbide Prepared by Spark Plasma Sintering

The Scientific World JOURNAL ◽

10.1155/2014/673276 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8

Author(s):

Xiaoyong Ren ◽

Zhijian Peng ◽

Zhiqiang Fu ◽

Chengbiao Wang

Keyword(s):

Mechanical Properties ◽

Spark Plasma Sintering ◽

Tantalum Carbide ◽

Uniaxial Pressure ◽

Cemented Carbides ◽

X Ray Diffraction ◽

Microstructure And Mechanical Properties ◽

Plasma Sintering ◽

Spark Plasma ◽

Microscopy Examination

Ultrafine tungsten carbide-nickel (WC-Ni) cemented carbides with varied fractions of silicon carbide (SiC) nanowhisker (0–3.75 wt.%) were fabricated by spark plasma sintering at 1350°C under a uniaxial pressure of 50 MPa with the assistance of vanadium carbide (VC) and tantalum carbide (TaC) as WC grain growth inhibitors. The effects of SiC nanowhisker on the microstructure and mechanical properties of the as-prepared WC-Ni cemented carbides were investigated. X-ray diffraction analysis revealed that during spark plasma sintering (SPS) Ni may react with the applied SiC nanowhisker, forming Ni2Si and graphite. Scanning electron microscopy examination indicated that, with the addition of SiC nanowhisker, the average WC grain size decreased from 400 to 350 nm. However, with the additional fractions of SiC nanowhisker, more and more Si-rich aggregates appeared. With the increase in the added fraction of SiC nanowhisker, the Vickers hardness of the samples initially increased and then decreased, reaching its maximum of about 24.9 GPa when 0.75 wt.% SiC nanowhisker was added. However, the flexural strength of the sample gradually decreased with increasing addition fraction of SiC nanowhisker.

Download Full-text

Mechanical properties and rapid consolidation of binderless nanostructured tantalum carbide

Ceramics International ◽

10.1016/j.ceramint.2009.06.012 ◽

2009 ◽

Vol 35 (8) ◽

pp. 3395-3400 ◽

Cited By ~ 44

Author(s):

Byung-Ryang Kim ◽

Kee-Do Woo ◽

Jung-Mann Doh ◽

Jin-Kook Yoon ◽

In-Jin Shon

Keyword(s):

Mechanical Properties ◽

Tantalum Carbide

Download Full-text

Effect of alloying elements on the composition of carbide phases and mechanical properties of the matrix of high-carbon chromium–vanadium steel

The Physics of Metals and Metallography ◽

10.1134/s0031918x17010070 ◽

2017 ◽

Vol 118 (1) ◽

pp. 81-86 ◽

Cited By ~ 1

Author(s):

V. I. Titov ◽

L. V. Tarasenko ◽

A. N. Utkina

Keyword(s):

Mechanical Properties ◽

Alloying Elements ◽

High Carbon ◽

Carbide Phases ◽

The Matrix ◽

Effect Of Alloying

Download Full-text

Effect of Ta and W Additions on Microstructure and Mechanical Properties of Tilt-Cast Ti-45Al-5Nb-2C Alloy

Metals ◽

10.3390/met11122052 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2052

Author(s):

Juraj Lapin ◽

Kateryna Kamyshnykova

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Volume Fraction ◽

Vacuum Induction Melting ◽

Nominal Composition ◽

Induction Melting ◽

Carbide Phases ◽

Microstructure And Mechanical Properties ◽

B2 Phase ◽

Carbide Particles

The effect of Ta and W additions on microstructure and mechanical properties of tilt-cast Ti-45Al-5Nb-2C (at.%) alloy was investigated. Three alloys with nominal composition Ti-45Al-5Nb-2C-2X (in at.%), where X is Ta or W, were prepared by vacuum induction melting in graphite crucibles followed by tilt casting into graphite moulds. The microstructure of the tilt-cast alloys consists of the α2(Ti3Al) + γ(TiAl) lamellar grains, single γ phase, (Ti,Nb,X)2AlC particles with a small amount of (Ti,Nb,X)C, and β/B2 phase identified only in W containing alloy. The EDS analysis shows that Ta segregates into the carbide particles and reduces dissolution of Nb in both (Ti,Nb,Ta)C and (Ti,Nb,Ta)2AlC phases. The alloying with W reduces Nb content in both carbide phases and leads to stabilisation of β/B2 phase in the lamellar α2 + γ regions. The alloying with Ta and W does not affect the volume fraction of the carbide particles but influences their size and morphology. While the alloying with Ta and W has no significant effect on Vickers hardness and the indentation elastic modulus of the studied alloys, the addition of Ta affects the nanohardness and elastic modulus of the (Ti,Nb,Ta)2AlC phase. The addition of W significantly increases the Vickers microhardness of the lamellar α2 + γ regions.

Download Full-text