CERAMICSINTERNATIONAL

Available online at www.sciencedirect.com

http://dx.doi.org0272-8842/& 20

nCorrespondinE-mail addre

2 (2016) 650–656

Ceramics International 4

www.elsevier.com/locate/ceramint

Microstructure and mechanical properties of B4C–TiB2 composites preparedby reaction hot pressing using Ti3SiC2 as additive

Ping Hea,b, Shaoming Donga,n, Yanmei Kana, Xiangyu Zhanga, Yusheng Dinga

aState Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences,1295 Dingxi Road, Shanghai 200050, China

bUniversity of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China

Received 30 July 2015; received in revised form 27 August 2015; accepted 28 August 2015Available online 6 September 2015

Abstract

B4C–TiB2 composites were fabricated via reaction hot pressing at 2100 1C under a pressure of 25 MPa, using B4C and Ti3SiC2 powders as rawmaterials. The phase transformations, microstructure and mechanical properties were investigated by XRD, TG–DTA, SEM, TEM and EDS. It isfound that the SiC and TiB2 particles are homogenously dispersed in the B4C–TiB2 composites, where nano-sized TiB2 particles are mainlylocated within the B4C matrix grains, while the large-sized TiB2 particles at the matrix grains boundaries. Due to the pinning effect of SiC andTiB2 particles on B4C grain growth, the grain size of the composite is significantly reduced, leading to a great improvement of the mechanicalproperties. B4C–TiB2 composite prepared from B4C-10 wt% Ti3SiC2 starting powder shows high flexural strength, fracture toughness and micro-hardness of 592 MPa, 7.01 MPa m1/2 and 3163 kg/mm2, respectively. Crack deflection and crack bridging are most likely the potentialtoughening mechanisms in the composites. Furthermore, according to the XRD and TG–DTA analysis, the possible reaction mechanisms leadingto the in-situ formation of TiB2 were proposed.& 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Keywords: Ti3SiC2; Reaction hot pressing; Phase transformation; Microstructure and mechanical properties

1. Introduction

Boron carbide (B4C) ceramics has received wide attentionfor high temperature structural applications owing to a numberof unique properties, such as low density, high melting point,high hardness, high elastic modulus and good abrasionresistance [1–3]. Despite that, the full potential usage of thematerial is rather limited because of its extremely poorsinterability (elevated sintering temperature 42200 1C) andthe high susceptibility to brittle failure ( fracture toughness2–3 MPa m1/2).

Early studies showed that the addition of secondary phasesinto B4C by forming multiphase composites, e.g. B4C/HfB2[4], B4C/CrB2 [5], B4C/TiB2 [6–9], B4C/SiC [10–11] andB4C/TiC [12], could significantly improve the mechanical

/10.1016/j.ceramint.2015.08.16015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

g author. Tel.: þ86 21 52414324; fax: þ86 21 52414903.ss: smdong@mail.sic.ac.cn (S. Dong).

property as well as sinterability of the material. Among them,B4C composite reinforced with TiB2 particles is particularlyattractive due to its high melting point, high elastic modulus,superior wear resistance and good chemical stability [13–14].However, to achieve a good balance among different aspectsof the mechanical properties of the material, it is still difficult.For instance, hot-pressed B4C–TiB2 composite prepared by Rushowed high strength and toughness of 506 MPa and9.4 MPa m1/2, respectively, but the hardness was just only23.6 GPa [15]. In comparison, hot-pressed B4C–TiB2 compo-site prepared by J.Vleugels showed a combination of highstrength and high toughness of 867 MPa and 29 GPa, while thefracture toughness was modest (4.5 MPa m1/2) [16]. Similarphenomenon was also observed by Yamada. Reaction hot-pressed B4C–TiB2 composite prepared by Yamada showedhigh strength of 866 MPa, with a low toughness of about3.2 MPa m1/2 [17]. All these results indicate that more work

www.sciencedirect.com/science/journal/02728842http://dx.doi.org/10.1016/j.ceramint.2015.08.160http://crossmark.crossref.org/dialog/?doi=10.1016/j.ceramint.2015.08.160&domain=pdfwww.elsevier.com/locate/ceraminthttp://dx.doi.org/10.1016/j.ceramint.2015.08.160http://dx.doi.org/10.1016/j.ceramint.2015.08.160http://dx.doi.org/10.1016/j.ceramint.2015.08.160mailto:smdong@mail.sic.ac.cn

P. He et al. / Ceramics International 42 (2016) 650–656 651

should be done to improve the full aspects of mechanicalproperties of the materials.

On the basis of above, in this study, we explored thefeasibility of preparation of the B4C–TiB2 composites viareaction hot pressing using B4C and Ti3SiC2 powders as rawmaterials. We expected that the addition of Ti3SiC2 reactedwith B4C and in situ generated TiB2, the fine TiB2 grains weredispersed homogeneously in B4C matrix, forming a kind ofcomplicated intragranular/intergranular microstructure andenhancing the strength and hardness. In addition, crackdeflection and crack bridging induced by TiB2 grains due toresidual stress resulting from thermal expansion mismatchbetween B4C and TiB2 improved the fracture toughness. Theresults show that the composite obtained possesses a signifi-cant improvement of the overall mechanical properties, and agood balance among strength, toughness and hardness isachieved. The formation mechanism, microstructure andmechanical properties of the composite are discussed.

Fig. 2. XRD patterns of the as-received (a) B4C, (b) Ti3SiC2 and (c) B4CþTi3SiC2 mixture powders.

2. Materials and methods

2.1. Materials

Commercially available Ti3SiC2 (Shanghai yuehuan newmaterial technology co., Ltd., China, 98% purity) and B4Cpowders (Dalian Jinma Boron Technology Group Co., Ltd.,China, 98.5% purity) were used as starting materials. Fig. 1shows the SEM images of the as received Ti3SiC2 and B4Cpowders. The Ti3SiC2 powder show aggregated particles ofo5 μm in size, whereas the B4C powder is composed ofirregular-shaped particles of o4 μm and relatively welldispersed. X-ray diffraction (XRD) analysis shown in Fig. 2indicates that the primary crystalline phases presenting in theTi3SiC2 and B4C powders are Ti3SiC2 and B4C, with tinyamounts of B2O3 and TiC impurities, respectively. Designatedamounts of B4C and Ti3SiC2 (0 wt%, 5 wt%, 10 wt%) powderswere weighed and mixed by ball milling in ethanol for 24 hwith boron carbide grinding media, then dried in air atmo-sphere. The resultant powder mixture was screened through a60-mesh nylon sieve and stored for later use.

Fig. 1. Typical SEM images of the as-rece

2.2. Reaction hot-pressing

Reaction hot-pressing was carried out using a hot-pressingapparatus in Ar atmosphere. The ball-milled B4Cþ Ti3SiC2powder mixtures were loaded into a graphite die with adiameter of 80 mm and a height of 150 mm, then heated to2100 1C at a heating rate of 10 1C /min, and dwelled for60 min under a maximum applied pressure of 25 MPa. Afterthat, the applied mechanical pressure was removed and theelectric power was switched off to allow the sample to cool toroom temperature.

2.3. Characterizations

The densities of the sintered samples were measured via theArchimedes method using distilled water as the medium.Flexural strength was measured through three-point-bendingtest on five specimens (3� 4x40 mm3) with a span of 30 mmand crosshead speed of 0.5 mm/min by universal machine(Model 5566, Instron Company, U.K). Fracture toughness wasevaluated by single edge notched beam test with a span of16 mm and crosshead speed of 0.05 mm/min, five sampleswere tested. The test bars, 2� 5� 30 mm3 in dimension, werenotched by electromachining with a 0.2 mm diameter Mo line.

ived (a) Ti3SiC2 and (b) B4C powders.

P. He et al. / Ceramics International 42 (2016) 650–656652

The notches were about 0.2 mm in width and 2.5 mm in depth.The test bars were ground and polished with a series ofdiamond pastes to a surface roughness of 0.5 μm, and theiredges were beveled before testing. The microstructure wascharacterized by scanning electron microscopes (SEM, JSM-6700F) and transmission electron microscope (TEM, JEOL-2100F). The phase assemblages of the sintered products wereanalyzed by X-ray diffraction (XRD) using CuKa radiation at40 kV tube voltage and 450 mA current.

The reaction mechanisms during high temperature treatmentof the B4Cþ10 wt% Ti3SiC2 mixed powder were investigatedas described below. First, the thermal effects and weightchanges of the B4Cþ10 wt% Ti3SiC2 powder mixture duringheating was analyzed by thermogravimetric (TG) and differ-ential thermal analysis (DTA) techniques from room tempera-ture to 1500 1C with a heating rate of 10 1C/min in high purityAr (99.99%) atmosphere. Then, B4Cþ10 wt% Ti3SiC2 mixedpowder were heat treated in Ar atmosphere from 900 to1600 1C for 1 h. The heat treated samples were characterizedwith XRD, and the chemical reactions occurred in the systemwere investigated.

3. Results and discussion

3.1. Reaction mechanisms of B4C and Ti3SiC2 mixture at hightemperature

The TG–DTA curves of B4Cþ10 wt% Ti3SiC2 mixedpowder heat treated from 100 to 1500 1C are shown inFig. 3. A broad endothermic peak centered at 1295 1C wasobserved on the DTA curve, while two weight losses occurringat the temperature ranges of 300–500 1C and 1100–1500 1Care observed on the TG curve. The low temperature weightloss (0.41%) should correspond to the pyrolysis of organiccontaminants introduced in the powder mixture during ballmilling process, where a nylon pot was used. The weight lossat high temperature is most likely associated with volatilizationor the carbothermal reduction of B2O3 impurity in the samples,as will be revealed later.

Fig. 3. TG–DTA curves of the as-received B4Cþ 10 wt% Ti3SiC2 mixturepowder.

The XRD patterns of B4Cþ10 wt% Ti3SiC2 mixed powderheat treated from 900 to 1600 1C in Ar atmosphere for 1 h areshown in Fig. 4. It can be seen that no obvious changes in theXRD pattern occur when the heat treatment temperatures arebelow 1200 1C. The samples in these cases show distinctivediffraction peaks of only B4C, Ti3SiC2, TiC and B2O3, noadditional new phases are detected. This indicates the absenceof noticeable reaction between Ti3SiC2 and B4C at temperaturebelow 1200 1C. However, when the heat-treatment temperatureincreased to be 1200 1C, radical changes in the XRD patternoccur. The diffraction peaks of Ti3SiC2 and B2O3 disappear,meanwhile diffraction peaks of TiB2 new phase are noticed,together with an obvious increase in the peak intensities ofTiC. Such radical changes in the XRD pattern implies thecomplete reaction between Ti3SiC2 and B4C to form TiB2 andTiC (reaction (1)), as well as the removal of B2O3 from thesample through chemical reaction with carbon (reaction (2)).

B4CþTi3SiC2-2TiB2þTiCþSiCþC (1)

2B2O3þ7C-B4Cþ6CO (2)

As the heat-treatment temperature further increased, thediffraction peaks of TiC phase are reversely decreased. At thesame time, the diffraction peaks of TiB2 become continuouslystronger. At 1600 1C, no diffraction peaks of TiC can bedetected, suggesting the complete conversion of TiC to TiB2through reaction with B4C (reaction (3)).

B4Cþ2TiC-2TiB2þ3C (3)

On the basis of the above results, the overall reaction in thesystem during heat-treatment of the B4Cþ10 wt% Ti3SiC2powder mixture can be described as reaction (4), if the B2O3impurity in the starting powder is ignored:

3B4Cþ2Ti3SiC2-6TiB2þ2SiCþ2C (4)

This reaction starts at 1200 1C and ended at 1600 1C withthe in-situ formation of TiB2 and SiC. However, because thecontent of SiC formed in the material is very small (2 wt%)and may be below the detecting limitation of XRD technique,its presence in the material is not reflected on the XRD patternsas found above.

3.2. Mechanical properties and Microstructure

Table. 1 lists the composition, density, flexural strength,fracture toughness and hardness of the three ceramics inves-tigated in this study. It can be seen that the composite preparedwith 10 wt% Ti3SiC2 addition is nearly full dense with arelative density of 99.6%, and optimal flexural strength,toughness and hardness of 592 MPa, 7.01 MPa m1/2 and3163 kg/mm2 respectively. Whereas monolithic B4C sinteredunder similar conditions achieved a relative density of 98.6%together with relatively low flexural strength, toughness and

Fig. 4. XRD patterns of the as-received B4Cþ10 wt% Ti3SiC2 powder mixtures heat-treated at different temperatures for 1 h.

Table 1Mechanical properties of the B4C–TiB2 composite.

wt% of Ti3SiC2 Measured density g/cm3 Calculated density g/cm3 Relative density % flexural strength MPa fracture toughness MPa.m1/2 Hv kg/mm2

0 2.4970.01 2.52 98.8 389728 4.4370.23 30837555 2.5370.01 2.58 98.1 533752 6.7370.26 314075610 2.6470.01 2.65 99.6 592710 7.0170.28 3163785

P. He et al. / Ceramics International 42 (2016) 650–656 653

hardness of 389 MPa, 4.43 MPa m1/2 and 3083 kg/mm2. Thepossible explanation for the improved density can be inter-preted as follows. The chemical reaction between B4C andTi3SiC2 will cause deviations of B4C from its stoichiometry,and thereby increase the concentration of structural vacanciesand lattice distortion in it [18]. This activates the latticediffusion of boron and carbon atoms, leading to enhancedmass transport and densification [18–19]. In addition, theapplication of high pressure for consolidation results in highstress at the particle contact points. The stress gradient at thecontact points can act as a driving force for mass transport,which is beneficial for sintering [19].

SEM micrographs of the fracture surface of the B4Cceramics and composites support the mechanical results shownin Table 1. As shown in Fig. 5(a), the two composites exhibitsimilar XRD pattern, there are only diffraction peaks of B4Cand TiB2, without any additional phases. The correspondingback-scattered electron images of fracture surface of the twocomposites are also shown in Fig. 5(c) and (d). In the figure,the dark gray phases are B4C and the small bright white phasesare TiB2. White TiB2 phases of fine sizes are homogenouslydispersed in the dark gray B4C matrix, which mainly resultsfrom the reaction between B4C and Ti3SiC2. Especially for thecomposites with 10 wt% Ti3SiC2, the mean size of TiB2 grainsis less than 1 μm and a large amount of sub-micrometer TiB2grains are dispersed within the B4C grains, indicating theformation of intragranular TiB2 structure in the composite. Inorder to distinguish SiC phase, back-scattered electron imagesof surface of the composites with 10 wt% Ti3SiC2 arepresented in Fig. 5(e). EDS (Fig. 5(f)) shows that the gray

phases are SiC, and SiC phases are dispersed uniformly in thedark gray B4C matrix, mean size of SiC grains is below 1 μm.As for the smaller TiB2 grains, TEM were used for furtherobservation. Fig. 6 shows representative TEM images ofintragranular and intergranular TiB2 grains and the high-resolution. The black zones located in B4C grains by EDSand electron diffraction analyses are TiB2 grains with ahexagonal crystal structure. According to the difference intheir location, TiB2 particles can be classified into two types,i.e. intragranular and intergranular ones. The intragranularTiB2 particles are confined within large boron carbide grains,their sizes are in the range of tens to several hundrednanometers in Fig. 6(a). As shown in Fig. 6(b), the inter-granular TiB2 particles are located at the matrix grainboundaries or triple junctions, and generally above onemicrometer in size, much larger than their intragranularcounterparts. It should be noted that the grain boundariesbetween SiC, TiB2 and B4C grains are not as straight as B4Cgrain boundaries. The irregularly curved grain boundariesresulting from SiC and TiB2 grains indicate the pinning effectof SiC and TiB2 grains on B4C grains. In addition, the nano-particles or sub-micrometer particles located within B4C grainsare prone to form sub-boundary structure in composites underthe presence of internal stress, which can refine matrix grainsshown in Fig. 5(d) and contribute to the improvement of themechanical properties of the composites, the potential hardnessdecrease caused by SiC and TiB2 formation in the composite iswell compensated.The SEM micrographs of the crack propagating on the

polished surface of B4C–TiB2 composite are shown in Fig. 7.

TiB2

SiC

B4C

TiB2

B4C

TiB2

Fig. 5. (a) XRD, (b–d) SEM images of the fracture surfaces of B4C–TiB2 composites prepared from B4CþTi3SiC2 mixtures containing (b) 0 wt%, (c) 5 wt% and(d) 10 wt% of Ti3SiC2 and (e–f) SEM images of surface and EDS of B4C–TiB2 composites prepared containing 10 wt% Ti3SiC2.

P. He et al. / Ceramics International 42 (2016) 650–656654

It can be seen that in situ formed TiB2 phase does not changefracture mode of the monolithic B4C ceramic, which is stilldominantly transgranular fracture. It can be also concludedfrom transgranular fracture that the good bonding strengthexists between B4C and TiB2 phase interface. As shown inFig. 7, crack bridging and obvious crack deflection by micron-sized TiB2 grains can be seen in the crack propagation. Due tothermal expansion coefficient difference between B4C(4.5� 10�6/k) and TiB2 (8.1� 10�6/k), residual thermalstress arises in the composite [20–22]. The stress field imposesa strong impact on the crack propagation behavior, makingcrack deflection and bridging by the TiB2 secondary phase

particles. This may be effective barriers for crack propagationand can consume much crack propagation energy. In this way,the fracture toughness of the composite is improved.

4. Conclusions

In short, B4C–TiB2 composite of high flexural strength,hardness and fracture can be prepared by the reaction of B4C andTi3SiC2 powder route with hot pressing. TiB2 particles are locatedboth intragranularly and intergranularly in the B4C matrix,showing a strong pinning effect on B4C grain growth. Thisresults in a significant refinement of the microstructure of the

TiB2

B4CTiB2

B4C

Fig. 6. TEM images of B4C–TiB2 composites showing (a) nano-size TiB2 particles entrapped in B4C grains and (b) large-size TiB2 particles located at matrix grainboundaries or triple junctions; (c) EDS and (d) corresponding electron diffraction and high resolution image of a TiB2 particle.

Crack bridging

Crack deflection

TiB2

Fig. 7. Crack propagation behavior of the polished surface in B4C–TiB2composite.

P. He et al. / Ceramics International 42 (2016) 650–656 655

composite and great improvement of its mechanical properties.Apart from that, crack deflection and crack bridging by micron-sized TiB2 grains may be also the main toughening mechanisms.The composite fabricated from B4C-10 wt% Ti3SiC2 startingpowder shows the optimal mechanical properties, with flexuralstrength, toughness and hardness of 592 MPa, 7.01 MPa m1/2 and

3163 kg/mm2, respectively. In comparison with the B4C–TiB2composites reported before, a well balance in the strength,toughness and hardness of the material is achieved.

Acknowledgments

The financial support from the “National High TechnologyResearch and Development Program” (No: 2013AA030703),“National Natural Science Foundation of China” (No:51272265) and “The Innovation Project of The Chinese Academyof Sciences, Shanghai Institute of Ceramics” (No: Y22ZC6160G)are greatly acknowledged.

References

[1] Vladislav Domnich, Sara Reynaud, Richard A. Haber, Manish Chhowalla,Boron carbide: structure, properties, and stability under stress, J. Am. Ceram.Soc. 94 (11) (2011) 3605–3628.

[2] F. Thevenot, Boron carbide – a comprehensive review, J. Eur. Ceram.Soc. 6 (1990) 205–225.

[3] G.I. Kalandadze, S.O. Shalamberidze, A.B. Peikrishvili, Sitering of boronand boron carbide, J. Solid State Chem. 154 (2000) 194–198.

http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref1http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref1http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref1http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref2http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref2http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref3http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref3

P. He et al. / Ceramics International 42 (2016) 650–656656

[4] K. Sairam, J.K. Sonber, T.S.R.Ch Murthy, C. Subramanian, R.C. Hubli,A.K. Suri, Development of B4C-HfB2 composites by reaction hotpressing, Int. J. Refract. Met. Hard Mater. 35 (2012) 32–40.

[5] Suzuya Yamada, Kiyoshi Hirao, Yukihiko Yamauchi, Shuzo Kanzaki,B4C–CrB2 composites with improved mechanical properties, J. Eur.Ceram. Soc. 23 (2003) 561–565.

[6] I. Bogomol, T. Nishimura, O. Vasylkiv, Y. Sakka, P. Loboda, Micro-structure and high-temperature strength of B4C–TiB2 composite preparedby a crucibleless zone melting method, J. Alloy. Compd. 485 (2009)677–681.

[7] Q.Q. Lin, S.M. Dong, P. He, H.J. Zhou, J.B. Hu, Microstructure andproperty of TiB2 reinforced reaction-bonded B4C composites, J. Inorg.Mater. 30 (2015) 667–672.

[8] Aiju Li, Yuhua Zhen, Qiang Yin, Laipeng Ma, Yansheng Yin, Micro-structure and properties of (SiC, TiB2)/B4C composites by reaction hotpressing, Ceram. Int. 32 (2006) 849–856.

[9] Mehri Mashhadi, Ehsan Taheri-Nassaj, Maryam Mashhadi, VincenzoM. Sglavo, Pressureless sintering of B4C–TiB2 composites with Aladditions, Ceram. Int. 37 (2011) 3229–3235.

[10] Xianwu Du, Zhixiao Zhang, Weimin Wang, Hao Wang, Zhengyi Fu,Microstructure and properties of B4C–SiC composites preparedbypolycarbosilane-coating/B4C powder route, J. Eur. Ceram. Soc. 34(2014) 1123–1129.

[11] Zhixiao Zhang, Xianwu Du, Zili Li, Weimin Wang, Jinyong Zhang,Zhengyi Fu, Microstructures and mechanical properties of B4C–SiCintergranular/intragranular nanocomposite ceramics fabricated from B4C,Si, and graphite powders, J. Eur. Ceram. Soc. 34 (2014) 2153–2161.

[12] Deng Jianxin, Sun Junlong, Microstructure and mechanical properties ofhot-pressed B4C/TiC/Mo ceramic composites, Ceram. Int. 35 (2009)771–778.

[13] Huimin Xiang, Zhihai Feng, Zhongping Li, Yanchun Zhou, Temperature-dependence of structural and mechanical properties of TiB2: a firstprinciple investigation, J. Appl. Phys. 117 (2015) 225902.

[14] Guolong Zhao, Chuanzhen Huang, Hanlian Liu, Bin Zou, Hongtao Zhu,Jun Wang, Microstructure and mechanical properties of TiB2–SiCceramic composites by Reactive Hot Pressing, Int. J. Refract. Met. HardMater. 42 (2014) 36–41.

[15] XinYan Yue, ShuMao Zhao, Peng L, Qing Chang, HongQiang Ru,Synthesis and properties of hot pressed B4C–TiB2 ceramic composite,Mater. Sci. Eng. A 527 (2010) 7215–7219.

[16] S.G. Huang, K. Vanmeensel, O.J.A. Malek, O. Van der Biest,J. Vleugels, Microstructure and mechanical properties of pulsed electriccurrent sintered B4C–TiB2 composites, Mater. Sci. Eng. A 528 (2011)1302–1309.

[17] Suzuya Yamada, Kiyoshi Hirao, Yukihiko Yamauchi, Shuzo Kanzaki,High strength B4C–TiB2 composites fabricated by reaction hot-pressing,J. Eur. Ceram. Soc. 23 (2003) 1123–1130.

[18] L. Levin, N. Frage, M.P. Dariel, The effect of Ti and TiO2 additions onthe pressureless sintering of B4C, Met. Mater. Trans. 30 (12) (1999)3201–3210.

[19] P. Larsson, N. Axen, S. Hogmark, Improvements of the microstructureand erosion resistance of boron carbide with additives, J. Mater. Sci. 35(2000) 3433–3440.

[20] Wenbin Zhou, Rubing Zhang, Shigang Ai, Yongmao Pei, Daining Fang,Analytical modeling of thermal residual stresses and optimal design ofZrO2/(ZrO2þNi) sandwich ceramics, Ceram. Int. 41 (6) (2015)8142–8148.

[21] Ryan M. White, Elizabeth C. Dickey, The effects of residual stressdistributions on indentation-induced microcracking in B4C–TiB2 eutecticceramic composites, J. Am. Ceram. Soc. 94 (11) (2011) 4032–4039.

[22] M. Taya, S. Hayashi, A.S. Kobayashi, H.S. Yoon, Toughening of aparticulate-reinforced ceramic-matrix composite by thermal residualstress, J. Am. Ceram. Soc. 73 (5) (1990) 1382–1391.

http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref4http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref4http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref4http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref4http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref4http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref5http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref5http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref5http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref5http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref5http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref6http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref6http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref6http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref6http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref6http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref6http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref7http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref7http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref7http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref7http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref7http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref8http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref8http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref8http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref8http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref8http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref9http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref9http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref9http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref9http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref9http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref10http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref10http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref10http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref10http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref10http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref10http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref11http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref11http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref11http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref11http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref11http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref11http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref12http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref12http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref12http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref12http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref13http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref13http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref13http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref13http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref14http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref14http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref14http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref14http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref14http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref15http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref15http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref15http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref15http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref15http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref16http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref16http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref16http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref16http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref16http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref16http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref17http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref17http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref17http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref17http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref17http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref18http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref18http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref18http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref18http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref18http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref19http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref19http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref19http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref20http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref21http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref21http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref21http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref21http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref21http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref22http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref22http://refhub.elsevier.com/S0272-8842(15)01686-7/sbref22

Microstructure and mechanical properties of B4C–TiB2 composites prepared by reaction hot pressing using Ti3SiC2 as additiveIntroductionMaterials and methodsMaterialsReaction hot-pressingCharacterizations

Results and discussionReaction mechanisms of B4C and Ti3SiC2 mixture at high temperatureMechanical properties and Microstructure

ConclusionsAcknowledgmentsReferences