Effect of the pressureless post-sintering on the hot isostatic pressed Al2O3 prepared from the oxidized AlN powder. Clough, Y. Geffen, and J.J. Wlassich: Acta Metall., 1991, vol. 30, pp. M.F. Res. 283142. The degradation is usually accelerated at elevated temperatures in many industrial applications17. Proc Int. 42540. B.K. M.V. The pressure is applied with a gas (usually inert) and, so, is isostatic. Lavish Kumar Singh, Alok Bhadauria, Tapas Laha, Yinqiu Huang, Guohong Chen, Wenming Tang, Afshin Nafari, Mehdi Malekan & Mehrab Lotfpour, Journal of Materials Science 31, pp. 35, pp. Semiatin, and R.L. 2nd Int. Sci. The sintering process is more difficult especially for AlN ceramic. H.P. Relat. S. Shima and M. Oyane: Int. 34, pp. 73(1), 7478. 3rd Int. 28(8), 19191928. Soc. The HIP and PS as well are using comparable higher sintering temperatures, which occured the transformation of the metastable -Al2O3 (Fig. The authors gratefully acknowledge the financial support by the DFG (Deutsche Forschungsgemeinschaft). Mater. DeLo: Progr. 11518. The equation used for calculation has been provided in Eq. Min, J.-H., Lee, J. Cao, Y. et al. In pure Mg, the fine MgO particles prevent the grain growth; however, the dragging force is not as great as that of the larger nanoparticles, which is why the grains can grow larger. on Hot Isostatic Pressing: Theory and Applications, Gaithersburg, MD, June 79, 1989, ASM INTERNATIONAL, Materials Park, OH, 1991, pp. Although the second phase of aluminum oxide can be observed only in the powders after 10 and 20h of oxidation time16. These negative effects were not sufficiently counteracted by the positive effect of the higher density. McMeeking: J. Appl. 26266. It has a really high degree of thermal stability and wear resistance while exhibiting a low density1. 2, Part 5, pp. ADS Indeed, we observed significant changes in the size and shape of the pores, the grain size and the distribution of the nanoparticles. 1116. Compared to the sintered samples, only the nanohardness of Mg increased significantly through HIP. 79396. 18(2), 337342 (2003). When castings are treated with HIP, the simultaneous application of heat and pressure eliminates internal voids and microporosity through a combination of plastic deformation, creep, and diffusion bonding; this process improves fatigue resistance of the component. Mester, and H.N.G. 92(3), 16491656. 43, pp. Local nanohardness measurements of the HIPed Mg nanocomposite revealed that these regions had a significantly lower nanohardness than the SiC-containing regions. 28591. Ceram. Phys. J. Mech Sci., 1992, vol. The process can be used to produce waste form classes. 40915. 32022. 34, pp 56373. I, pp. used the pressureless sintering in hydrogen to obtain Al2O3-SiC composites18. 3e. 72, pp. Hot isostatic pressing is a manufacturing process which utilizes elevated temperature and isostatic gas pressure to eliminate porosity and increase density in metals, ceramics, polymers, and composite materials. An inert gas is used so that the material does not chemically react. Google Scholar. 6367. Woodhead Publishing is an imprint of Elsevier, Cambridge, pp 349367, Chapter G.E. The intermediate unstable phases as -Al2O3, -Al2O3 can be developed during the transformation of AlN to Al2O320. R.S. Additionally, due to the longer process time of HIP (>1h compared to a few minutes for hot extrusion), there is more time for diffusion. 2), additionally at least 50 indents were made for local nanohardness measurements in each of the two different regions using grids of 31 indents with a distance between single indents of 10m. https://doi.org/10.1023/B:JMSC.0000044878.11441.90, Atkinson HV, Davies S (2000) Fundamental aspects of hot isostatic pressing: an overview. and cookie policy to learn more about the cookies we use and how we use your The phase and structural transformation of pure AlN (Fig. Sci. 2d,e). The process can be used to produce waste form classes. Sci. Duva and P.D. J Mater Res 7(06):15641583, Oliver WC, Pharr GM (2004) Measurement of hardness and elastic modulus by instrumented indentation: advances in understanding and refinements to methodology. 587606. Metallurgical and Materials Transactions A, https://doi.org/10.1007/s11661-000-0078-2, access via Growth kinetics and mechanisms of aluminum-oxide films formed by thermal oxidation of aluminum. 16570. applied the hot pressing at various temperatures of 1800, 1850, and 1900C and produced the AlN-Al2O3 with hardness between 14 and 16 GPa33. Ceram. et al. 797800. Slider with three articles shown per slide. Removal of forming agent and pre-burning stage (<800 C) The sintered samples (PS_3PS_20) have been heated at 1800C, 0.1MPa under H2 environment to complete the conversion cycle of AlN to Al2O3. We investigated the effect of HIP on the densification, the microstructure and the mechanical properties of a MgSiC nanocomposite with a reinforcement content of 1 vol% SiC nanoparticles compared to non-reinforced Mg. Anyone you share the following link with will be able to read this content: Sorry, a shareable link is not currently available for this article. This process can shrink steel canisters to minimize space in disposal containers and during transport. Jones: Scripta Mater., 1997, vol. and F.C.S; investigation, interpretation of data for the work, validation D.V., Zs.E.H, and M.F. Mater. HIP, Hot Isostatic Pressing, is one of material processing methods, which compresses materials by applying high temperature of several hundreds to 2000 C and isostatic pressure of several tens to 200MPa at the same time. This improves the material's mechanical properties and workability. Mater Sci Eng A 738:264272, Kamrani S, Penther D, Ghasemi A, Riedel R, Fleck C (2018) Microstructural characterization of Mg-SiC nanocomposite synthesized by high energy ball milling. The green beads are first sintered to a closed-pore condition or, alternatively, encapsulated in evacuated glass tubes (Fig. 88084. 3, pp. Even though we achieved an increase in density no increase in the mechanical properties was achieved, mainly due to grain growth and the development of SiC-free, non-reinforced regions. 56980. https://doi.org/10.1016/S0955-2219(01)00200-X. 53, pp. Mater. Kim: Powder Metallurgy World Congress, Les Editions de Physique, Les Ulis, 1994, EPMA, Shrewsbury, 1994, vol. Provided by the Springer Nature SharedIt content-sharing initiative. Mech. Ceram. 3d shows that the SiC-containing region has small equiaxed Mg grains, with a homogeneous distribution of SiC nanoparticles throughout the grains. P. Stutz, R. Aryanpour, O. Bouaziz, and C. Dellis: pp. Investigation of oxidized AlN at 3h. (a) XRD plots of oxidized AlN powder (O_3), HIP sintered (HIP_3) and sintered at H2 (PS_3), (b) SEM image of PS_3. Mater. Google Scholar. Sci., 1969, vol. Sintering in H2 caused the full transformation of AlN to -Al2O3 phase and their better densification. J Eur. https://doi.org/10.1023/A:1006512904173 (1998). Bulk sintered Al2O3 has been prepared by oxidization of AlN powder and combined sintering process, hot isostatic pressing (HIP) in N2 and pressureless sintering (PS) in H2 atmosphere. Apparent density values of HIP and PS sintered Al2O3 are in agreement with results of group of Kim et al.30. In this study, we present a novel powder based hot isostatic pressing (PHIP) treatment to enhance the tensile strength of PEEK manufactured through the material extrusion method. The causes of the above phenomena were closely related to the sintering mechanism. The arrows denote elongated pores which appear in black. Wieters: Rev. 33, 38593865. Soc., 1949, vol. When a certain amount of particles has accumulated, the grain boundary movement is stopped by Zener pinning, which also hinders recrystallisation. By submitting a comment you agree to abide by our Terms and Community Guidelines. Hot Isostatic Pressing - an overview | ScienceDirect Topics Mater. R.M. Mater. A.G.K. D.S. 33, pp. Powder metallurgy - Wikipedia Dudek, and W.A. https://doi.org/10.4416/JCST2018-00011 (2018). This improves the material's mechanical properties and workability. 691702. Densification of the Mg nanocomposites during HIP was lower than what we observed during hot extrusion [11]. Varanasi et al. G.W. Mater. M. Oyane, S. Shima, and Y. Kono: Bull. Dayton, and E.S. Hot isostatic pressing - Wikipedia R.L. This explains the high scatter of the results, and the higher Eeff of the nanocomposites as compared to the pure Mg. 20813. Am. The vertical black lines denote the standard deviation. Oxidation above 6h induced the presence of intermediary -Al2O3 phase. Hot Isostatic Press Sintering and Properties of Silicon Nitride - ACerS 9699. Averaging over both regions, we determined a grain size of 270nm. https://doi.org/10.1007/s10854-017-7243-5 (2017). 48, pp. Am. To the best of our knowledge, there are no reports regarding HIP of magnesium nanocomposites. 84. The increasing of hardness has been influenced by increasing of oxidization time of base AlN powder, minimal presence of AlN and grain size of -Al2O3. 3946. Downey: Int. J. Mech. The apparent density of the sintered samples has been measured using Archimedes method where the samples with surface porosity have been immersed in soap water for three days ensuring the complete filling of the pores. J. However, visualising dislocations in the hcp crystal structure is very complex and challenging, especially if the grain orientations of the nano-sized Mg grains in the TEM foil are not known. The average Vickers microhardness of all four material compositions and states is shown in Fig. The pressure is applied with a gas (usually inert) and, so, is isostatic. Conf. The micrometer size AlN powder has been oxidized in air at 900 C and sintered by hot isostatic pressing (HIP) at 1700C, 20MPa nitrogen atmosphere for 5h. Pressureless sintering (PS) has been applied for all HIP sintered samples in H2 gas at 1800 C for 10h. It has been shown that the oxidation caused a coreshell AlN/Al2O3 structure and the amount of Al2O3 increased with increasing of the oxidation time of the AlN powder. 34, pp. Mater Sci Eng R Rep 54(56):121285, Loh NL, Sia KY (1992) An overview of hot isostatic pressing. Janowski: Acta Metall. Nanohardness and Eeff were determined by the method described by Oliver and Pharr [13, 14]. The average Eeff of the HIPed materials, both in the non-reinforced Mg and in the reinforced state, statistically significantly decreased by 7.5 and 9.7%, respectively, compared to the sintered samples. Soc. On the other hand, Al2O3 is a simple covalent oxide of aluminum which is generally formed at the surface of pure aluminum. ADS The particle clustering can also be observed in cases of samples with oxidization time above 6h. In our previous study, it has been confirmed simultaneous growth of two different phases of aluminum oxide, -Al2O3 and the intermediary -Al2O3 (Fig. E. Olevsky, A. Maximenko, S. Van Dyck, L. Froyen, L. Delaey, and L. Buekenhout: Int. Hot Isostatic Pressing. 76 (4), pp. 176773. Oh, Stevens, R. Reaction sintering and microstructural development in the system Al2O3AlN, J. Eur. J. Mech. Technol., 1996, vol. The pressure and heat help to fill any pores on the surface of the component, thus optimising material properties and density. The comparative study of densities of HIP sintered and PS sintered samples showed the similar tendency. (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': Sci., 1992, vol. J. Mech. The HIP and PS sintered base (reference) AlN exhibited the lowest apparent density (2.57g/cm3, Fig. 44955. https://doi.org/10.1016/S0040-6090(02)00787-3 (2002). The pore shape and distribution and the characteristics of the nanoindents were investigated by scanning electron microscopy (SEM), using a Gemini SEM 500 (Zeiss, Germany) in secondary electron (SE) mode at an accelerating voltage of 8kV. Until now, only a few studies on HIP of metal-matrix composites exist. Cao et al. The morphology and the microstructure of the powders and sintered samples have been characterized by scanning electron microscopy (SEM). Pergamon Press, Oxford, Dieringa H (2011) Properties of magnesium alloys reinforced with nanoparticles and carbon nanotubes: a review. Lograsso: Mater. https://doi.org/10.1016/S0955-2219(96)00092-1 (1997). Orthop. Technol., 1996, vol. Nickel, stainless or mild steel, or other metals can be chosen depending on the desired redox conditions. })(window,document,'script','dataLayer','GTM-T9BND6P'); Cold isostatic pressing has the advantage for producing parts where the high initial cost of pressing dies cannot be justified or when very large or complex compacts are needed. S. Quaranta and L.B.P. In: 7th international scientific conference: achievements in mechanical & materials engineering 67(1):131136, Penther D, Ghasemi A, Riedel R, Fleck C, Kamrani S (2018) Effect of SiC nanoparticles on manufacturing process, microstructure and hardness of Mg-SiC nanocomposites produced by mechanical milling and hot extrusion. obtained hardness of 20.50.6 GPa presented a grain size of Al2O3~0.620.04m at the lowest HIP temperature (1300C)31. -Al2O3 is more stable at higher temperatures of~9501000C where kinetic factors play a lesser role29. Lograsso and D.A. 42, pp. de Monicault, D. Guichard, P. Stutz, and D. Bouvard: Proc. & Yoon, D.-H. Xue, J. M. et al. Davies and D.R.H. All post-sintered samples exhibited the main -Al2O3 phase. What is Sintering? (A Definitive Guide) - TWI J Mater Sci. However, achieving full density while keeping the ultrafine microstructure during the consolidation process is still a challenge. The effect of the pressureless post-sintering in hydrogen on the structural and mechanical properties of the hot isostatic pressed Al2O3 prepared by oxidized AlN powder has been studied. E. Olevsky, H.J. Int. In the macroscopic approach, the compact is treated as a continuous medium. I, pp. What is Sintering and Hot pressing? - Meetyou Carbide Conf. and JavaScript. The presence only the major -Al2O3 predicted the higher densification during sintering process (independently on sintering type) (Fig. Even though density increased indeed, we observed no increase in the mechanical properties, due to significant heterogeneity in the microstructure.
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