Sliding wear behavior of SPS processed TaC-containing Ti(CN)-WC-Ni/Co cermets against Silicon Carbide

Verma, Vikas,Kumar, B.V. Manoj Elsevier 2017 Wear: An international journal on the science and Vol.376 No.2

<P><B>Abstract</B></P> <P>Dense (>98.5%) TiCN-WC-Ni/Co cermets with or without TaC are prepared by spark plasma sintering technique at 1400°C and 70MPa pressure for 3min and their friction and wear properties are investigated against commercially available hard counterbody silicon carbide ball at 5, 10 or 20N load. Core-rim morphology is observed in SEM images of sintered samples which results due to dissolution and reprecipitation process. Vickers Hardness and fracture toughness varied from 15–17GPa and 8.79 to 9.51MPam<SUP>1/2</SUP>. Nano hardness of core-rim-binder phases of cermets lie between 11.14–26.01GPa. Maximum hardness and fracture toughness were obtained for Ti(CN)-5WC-10Ni-10Co-5TaC (in wt%) cermet. With change in the cermet composition and sliding load, coefficient of friction varied from 0.3 to 1.1. Wear rate of cermets varied from 4.7×10<SUP>−7</SUP> mm<SUP>3</SUP>/Nm to 2.2×10<SUP>−6</SUP> mm<SUP>3</SUP>/Nm and of worn SiC ball from 4.4×10<SUP>−7</SUP> mm<SUP>3</SUP>/Nm to 1.5×10<SUP>−6</SUP> mm<SUP>3</SUP>/Nm. Hard debris oxides are responsible for higher COF at low load of 5N and their compaction leads to the formation of tribolayer at high load of 20N. The worn surfaces of cermets are characterized by microcracking, tribolayer formation and spalling. The addition of TaC in TiCN-WC-Ni/Co cermets led to the refined carbide size having lowest contiguity of ceramic phase and attributed to reduced wear. Present research contributes in context of dry machining conditions and is conducted to explore the potential of new cermet material in severe wear conditions against hard material.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Present research is to explore the potential of new cermet material in severe sliding wear conditions against hard material. </LI> <LI> Effect of TaC as ternary carbide on mechanical and tribological behavior of SPSed processed TiCN-WC-Ni/Co cermets is studied. </LI> <LI> Present research contributes in context of dry wear conditions. </LI> <LI> The wear mechanisms are particularly elucidated in terms of cermet composition and sliding load. </LI> </UL> </P>

Tool Performance of New Wear-resistant Cermets

김용선,권원태,서문수,강신후 한국정밀공학회 2012 International Journal of Precision Engineering and Vol.13 No.6

Ti(C,N)-based cermets were recently designed for tool applications as they offer enhanced interfacial strength. Such a cermet exhibits a typical core/rim microstructure as found in conventional cermets. To determine the possibility of using new cermet as a cutting tool, Ti(C,N) along with various carbides, nitrides, solid-solution carbonitride such as (Ti,W)(C,N),and Ni were milled together, sintered into the size of SNGN120408 and used in turning the SM45C (AISI45). Commercial WC and cermet insert of an identical size were selected to compare its cutting capability with that of the home-made cermet tool. To ensure a fair comparison of the cutting performance, the optimal machining conditions for commercial WC, cermet and home-made cermet tools were obtained using the Taguchi method. Experiments under both optimal conditions showed the excellent cutting performance of the new home-made cermet tool. It is believed that the interface between core Ti(C,N)and rim phases has been improved significantly in the new cermets.

TiB$_2$-Fe 서메트의 소결성 및 기계적성질에 미치는 Mo첨가의 영향

최덕순 한국세라믹학회 1999 한국세라믹학회지 Vol.36 No.5

Fe and Fe-Mo binder were used to produce TiB2 based cermet by a pressureless sintering. The densification behaviour of TiB2-Fe-Mo cermet during liquid-phase sintering in argon was studied in relation to binder phase charactertics. The effects of Mo addition and sintering condition on the sintering behaviour and mechanical properties were also investigated. TiB2-based cermets with Fe-Mo binder composition showed a better sinterability than the cermets with only Fe binder. In TiB2-Fe-Mo cermet higher densities in the wide temperature range were obtained and also fully densified sintered cermet were obtained at 1873K The enhancement in the densification phenomenon of TiB2-Fe-Mo system can be explained by improved liquid phase wettability associated with the roles of Mo components as solute atoms. When Fe-Mo binders were used cermets with a finer grain size and enhanced mechanical properties wereproduced and new phases such as Fe2B and Mo2FeB2 were observed in the sintered cermet. The highest bending strength was obtained from the 20vol% Fe-Mo cermet and these hardness-fracture toughness combination in the wide binder compositions is better than that of TiB2-Fe cermet. In order to improve mechanical properties microstructure control with high purity powders is desirable because high purity powders prevent the formation of Fe2B and Mo2FeB2 phase which comsume the ductile binder phase.

Microstructure evolution and mechanical properties of (Ti_0.93W_0.07)C–<i>x</i>WC–20Ni cermets

Kim, Jiwoong,Kang, Shinhoo Elsevier 2011 Materials science & engineering. properties, micro Vol.528 No.7

<P><B>Research highlights</B></P><P>&z.rtrif; (Ti<SUB>0.93</SUB>W<SUB>0.07</SUB>)C–<I>x</I>WC–20Ni cermets have a uniform microstructure compared to conventional cermets. &z.rtrif; As increasing WC addition, the carbide particle size is decreased. &z.rtrif; Comparing to conventional Ti(CN)-based cermets, the solid solution cermets show superior hardness and toughness.</P> <P><B>Abstract</B></P><P>The microstructure and mechanical properties of (Ti<SUB>0.93</SUB>W<SUB>0.07</SUB>)C–<I>x</I>WC–20Ni cermets were investigated to determine the effect of WC addition on the Ti-based solid solution cermet, (Ti<SUB>0.93</SUB>W<SUB>0.07</SUB>)C–20Ni. (Ti<SUB>0.93</SUB>W<SUB>0.07</SUB>)C–20Ni exhibited a homogeneous microstructure with no core–rim structure; however, a core–rim structure was observed with the addition of WC. The carbide size decreased sharply with the addition of 15wt.% WC. After composition, very small coreless carbide (VSCC) particles abruptly emerged in the microstructure. These particles might be formed by homogeneous nucleation during the final stage of sintering and cooling after the outer rim formation period. With increasing WC addition, the hardness remained constant, whereas the toughness decreased. Compared with Ti(CN)-based cermets with similar compositions, the hardness and toughness of (Ti<SUB>0.93</SUB>W<SUB>0.07</SUB>)C–<I>x</I>WC–20Ni cermets exhibited higher values. The refined microstructure of Ti-based solid solution cermets is considered to be responsible for the superior mechanical properties.</P>

Development of a New Electrode for Micro-Electrical Discharge Machining (EDM) using Ti(C,N)-based Cermet

Yoo, Hyeon Kyu,Kwon, Won Tae,Kang, Shinhoo 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.4

Ti(C,N)-based cermets were recently designed for tool applications as they offer enhanced interfacial strength. These cermets exhibit a typical core/rim microstructure, as found in conventional cermets. To determine the possibility of using these new cermets as electrodes for electrical discharge machining (EDM), Ti(C,N) with carbides, nitride, solid-solution carbonitride such as (Ti,W)(C,N), and Ni were milled together, and sintered to manufacture an electrode to drill a micro-hole in a stainless steel thin plate (SS304) using micro-EDM. A commercial WC (tungsten carbide) electrode was selected to compare its machining capability with that of the homemade cermet electrode. To ensure a fair comparison of cutting performance, the optimal machining conditions for commercial WC, cermet, and the homemade cermet electrode were obtained using the Taguchi method and Grey relational analysis. Experiments under Taguchi and Grey relational optimal conditions showed excellent machining performance using the new homemade cermet electrode.

Electro-discharge machining performance of TiCN-based cermets

Manoj Kumar, B.V.,Ramkumar, J.,Basu, B.,Kang, S. MPR Pub. Services 2007 INTERNATIONAL JOURNAL OF REFRACTORY METALS AND HAR Vol.25 No.4

The present investigation aims at evaluating the die sinking electro-discharge machining (EDM) performance of TiCN-20wt.% Ni cermets containing 10wt.% of different secondary carbides: WC, NbC and TaC. Such performance is assessed in terms of making cavity of 1mm depth on a commercial high speed tool steel (HSS). The material removal rate (MRR) is found to be higher for TiCN-20wt.% Ni cermet; however tool wear ratio (TWR) is lower for TiCN-20Ni-10TaC cermet. The quality of cermet tool surface has been quantitatively assessed using surface roughness tester and it was observed that the roughness (R<SUB>a</SUB> or R<SUB>z</SUB>) of TiCN-20Ni-10TaC cermet tool surface is lower, when compared with that of other investigated cermets. SEM-EDAX analysis of EDM surfaces reveal melting and evaporation of the binder as well as pull-out and spalling of brittle carbonitride/carbide grains as the dominant wear mechanisms. The layer formation due to solidification of molten layer and/or transfer of material from workpiece is commonly observed for all the cermet tool surfaces.

Tribological Properties of Ti(C,N)-based Cermet after Hot Isostatic Pressing at High Nitrogen Pressure

Xiong Wei-hao,Zheng Li-yun,Yan Xian-mei 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Sintered Ti(C,N)-based cermets were treated with hot isostatic pressing (HIP) at different nitrogen pressures. The tribological properties of the treated cermets have been evaluated. The results show that a hard near-surface area rich in TiN formed after HIP treatment. The cermets treated at higher pressure had a relatively lower friction coefficient and specific wear rate. In all cases the microhardness of treated cermets is higher than that without HIP natridation. The wear mechanisms of cermets were hard particle flaking-off and ploughing. It was also found that the HIP natridation is well-suited for improving the tribological properties of cermets.

屑芋의 씨토란(種牛) 利用에 關한 硏究 I. 屑芋의 크기가 토란의 生育과 收量에 미치는 영향

최성규,윤경원 한국자원식물학회 2001 한국자원식물학회지 Vol.14 No.3

토란 재배시 관행적으로 이용가치가 적어서 버리는 설우(屑芋를 종우(種芋)로 활용하는 방법을 연구하고자 본 시험을 실시한 결과는 다음과 같다. 1. 토란의 출현은 종우(種芋)의 크기별로 약간의 차이가 인정되어 자우(子芋)인 설우(屑芋)나 소우(小芋)가 친우(親芋)보다 약간 빠른 경향이었으나 출현율은 친우가 높았다. 2. 생육은 자우(子芋)보다는 친우가 엽병장이 크고 엽병속수(葉炳束數)가 많아 양호하였으며, 자우(子芋)가 클수록 생육이 양호한 경 향이었다. 자우(子芋)중 설우(屑芋)도 엽병속이 1.5~2.6개 발생되어 정상적인 생장이 가능하였다. 3.토란 종우(種芋)의 크기에 따른 괴경(塊莖)과 부산물(副産物) 엽병(葉炳)의 수량은 자우(子芋)의 크기간에 차이가 인정되어 자우(子芋)가 클수록 수량이 증수되는 경향이었다. 또한 설우(屑芋)도 크기에 따라 10a 당730~1,680kg의 괴경(壞莖)과 100~310kg의 엽병(葉炳)을 생산할 수가 있어서 대면적의 재배시 종우(種芋)로 이용이 가능할 것으로 생각된다. In order to investigate the possibility of utilizing small cermet as a seed corm in taro, the small cermets classified by the weight were planted on April 30,2000. The effect of weight of small cermets(5,10, If,20,25, and 30g) and corms on the growth, yield, and quality of taro was compared to those raised from cermets. The larger the size of cormel was, the more number of leaves developed, and the higher the yield was. Also the growth of small cormel was normal, so we forecast that it is possible to use small cermet as seed corm in mass production of taro.

In-situ fabrication of TiC-Fe₃Al cermet

Kim, Yong-In,Seok An, Gye,Lee, Wonsik,Man Jang, Jin,Park, Bong-Geun,Jung, Yeon-Gil,Choi, Sung-Churl,Ko, Se-Hyun Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.8

<P><B>Abstract</B></P> <P>Titanium carbide has high hardness, resistance to oxidation and abrasion while iron aluminide has proper ductility as well as good strength and excellent oxidation resistance up to high temperatures. Therefore, it can be expected TiC-iron aluminide cermet to have excellent mechanical properties as a cutting tool and a wear-resistance material. In this study, mechanical milling and hot press sintering processes were used to manufacture in-situ TiC-Fe<SUB>3</SUB>Al cermet, whose microstructure and mechanical properties were examined according to the changes in volume fraction of TiC and milling time. After 48h of milling each mechanically alloyed powder crystallized in a TiC and Fe<SUB>3</SUB>Al biphasic material. The milled powder was hot-pressed at 1250℃ and 50MPa for 30min to obtain sintered bodies also consisting of only TiC and Fe<SUB>3</SUB>Al phases. The hard phase, TiC, had a size of 100–300nm with overall uniform distribution decreasing as the volume fraction of TiC increased. The hardness of each sintered body showed a linearly increasing tendency according to the increase in TiC content, the hardness for 90vol% TiC cermet being as high as 1813Hv. On the other hand, the bending strength was 1800MPa and 1780MPa when TiC volume fraction was 50% and 70%, respectively, while it showed an abrupt decrease up to 580MPa at 90% TiC volume fraction. Fe<SUB>3</SUB>Al phase is effective to toughening of TiC-Fe<SUB>3</SUB>Al cermet and the volume fraction of Fe<SUB>3</SUB>Al phase significantly influences the bending strength of the cermet.</P>

Influence of Microstructure Evolution on Mechanical Properties, Wear Resistance and Corrosion Resistance of Ti(C,N)-Based Cermet Tools with Various WC Additions

L. B. Zhao,N. Lin,X. Q. Han,C. Ma,Z. Y. Wang,Y. H. He 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

The efects of tungsten carbide addition on the microstructure, mechanical properties and corrosion resistance of Ti(C,N)-based cermets prepared by the sinter-HIP method are investigated through scanning electron microscope, X-ray difraction,electron back scattered difraction, mechanical test and electrochemical method. The results show that the appropriate WCaddition has an important infuence on promoting the formation of core-rim microstructure of cermet, increasing the wettability of ceramic phase and binder phase, and improving the mechanical properties. Ti(C,N)-based cermet with 5 wt% WCaddition has the highest hardness of 92.4 HRA and excellent wear resistance. However, excessive WC addition causes theappearance of slight white core phase containing plenty of W and Ti element in microstructure, which increases the fracturetoughness, and reduces the hardness and wear resistance of cermet. Additionally, the electrochemical result shows that theaddition of 5 wt% WC in cermet has the optimal corrosion resistance in 1 mol/L hydrochloric acid solution.