**1. Introduction**

[94] Lu, S.L., Qian, M., Yan, M., Tang, H.P, & StJohn, D. (2014) Unpublished materials.

rials Transactions A 37, no. 3 (2006): 559-566.

Metallurgy, 57, no.4(2014): 251-257.

(2014): 196-206.

106 Sintering Techniques of Materials

Institute, 1995.

press, 2014.

(2012): 491-494.

[95] Kar, S., T. Searles, E. Lee, G. B. Viswanathan, H. L. Fraser, J. Tiley, and R. Banerjee. Modeling the tensile properties in β-processed α/β Ti alloys. Metallurgical and Mate‐

[96] Collins, P. C., B. Welk, T. Searles, J. Tiley, J. C. Russ, and H. L. Fraser. Development of methods for the quantification of microstructural features in α+β-processed α/β ti‐

tanium alloys. Materials Science and Engineering: A 508, no. 1 (2009): 174-182. [97] Yan, M., Xu, W., Dargusch, M.S., Tang, H.P., Brand & M., Qian, M. (2014), Powder

[98] Yan, M., M. S. Dargusch, T. Ebel, and M. Qian. A transmission electron microscopy and three-dimensional atom probe study of the oxygen-induced fine microstructural features in as-sintered Ti–6Al–4V and their impacts on ductility. Acta Materialia 68

[99] Yan, M., Y. Liu, G. B. Schaffer, and M. Qian. In situ synchrotron radiation to under‐ stand the pathways for the scavenging of oxygen in commercially pure Ti and Ti–

[100] H.R. Ogden, R.L. Jaffee: The effects of carbon, oxygen, and nitrogen on the mechani‐ cal properties of titanium and titanium alloys, TML Report No 20 Battelle Memorial

[101] Soeda; Seiichi (Tokyo, JP), Fujii; Hideki (Futtsu, JP), Okano; Hiroyuki (Chigasaki, JP), Hanaki; Michio (Chigasaki, JP): US patent, No. 6063211, "High strength, high ductili‐

[102] Sun, Y.Y., Gulizia, S., Oh, C.H., Doblin, C., Yang, Y.F., Qian, M. Unpublished data.

[103] Okabe, T. H., Hirota, K., Kasai, E., Saito, F., Waseda, Y., & Jacob, K. T. (1998). Ther‐ modynamic properties of oxygen in RE–O (RE=Gd, Tb, Dy, Er) solid solutions. Jour‐

[104] Thompson, G. E., Skeldon, P., Zhou, X., Shimizu, K., Habazaki, H., & Smith, C. J. E. (2003). Improving the performance of aerospace alloys. Aircraft Engineering and

[106] Yan, M., Tang, H.P., Qian, M.. Scavangin of oxygen ad chlorine from powder metal‐ lurgy (PM) titanium and titanium alloys. In "Titanium Powder Metallurgy", (Edi‐ tors) Qian, M., Froes, F.H. Elsevier and Science Direct, ISBN: 978-0-12-800054-0, In

[107] Yan, M., Y. Liu, Y. B. Liu, C. Kong, G. B. Schaffer, and M. Qian. Simultaneous getter‐ ing of oxygen and chlorine and homogenization of the β phase by rare earth hydride additions to a powder metallurgy Ti–2.25 Mo–1.5 Fe alloy. Scripta Materialia 67, no. 5

6Al–4V by yttrium hydride. Scripta Materialia 68, no. 1 (2013): 63-66.

ty titanium-alloy and process for producing the same", 2000.

nal of alloys and compounds, 279(2), 184-191.

Aerospace Technology, 75(4), 372-379.

[105] Tang, H.P., & Qian, M. Unpublished data.

Metal matrix composites (MMC) reinforced with dispersed ceramic particles have received considerable interest over the years and are still in constant development in order to expand their applications in industry. It is a brilliant choice for applications that require mechanical strength and wear resistance. They combine a soft metal matrix with hard ceramic particles resistant to wear (Gordo, 200).

Different matrixes and reinforcements for MMC have been studied, and therefore studies have been conducted with various combinations of metal matrixes with reinforcement of ceramic powders aimed at obtaining composites with similar properties or superior to conventional steel tool. Carbides such as NbC, TaC, VC, and TiC have been combined with iron or steel powders to produce sintered composites. Niobium and tantalum carbide can be used for structural purposes and also for the production of refractory components, or as steel rein‐ forcement by dispersed particles. Particularly, reinforced steel has been used in the automotive and textile industries and also in the manufacture of high-speed cutting and ore milling tools (Martinelli, *et al*, 2007). Advances in research (Silva, 2005; Silva, *et al*, 2005; and Silva, *et al*, 2012) and marketing of steel reinforced with NbC and TaC particles have also contributed to add value to manufactured products strategically using mineral sources produced in north‐ eastern Brazil.

New techniques for the production of refractory metal carbides (WC, NbC, TaC, TaxNby) have been developed by synthesizing nanostructured carbides that provide improvement of diverse properties of materials compared to materials obtained by conventional methods (Medeiros, 2002 and Medeiro, et al, 2005). Uniform distribution and fine particle size of nanosized particles

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of the reinforcing phase added to steel provide homogeneous dispersion of these steel carbides into the matrix, thus providing uniformity of properties and allowing compounds to be used in a variety of applications.

In the production of metal composites reinforced with carbides, powder metallurgy offers some economic and technological advantages in relation to other competing processes such as low cost of raw material processing and relatively low temperatures involved in the process. As the microstructure of the sintered steel is the result of process parameters (time, milling speed, compaction pressure, sintering time and temperature, sintering in solid or liquid state) and also the characteristics of starting powders (size and particle size distribution, compres‐ sibility and chemical purity); any changes in these parameters also affect the sintering kinetics, with wide variations in their microstructure and consequently their performance in relation to specific application. The use of the technique Powder Metallurgy (PM) in the manufacture of MMC composites is increasing.
