Fabrication of Zinc–Tungsten Carbide candidate for potential applications in biodegradable implants [4,10]. Due to a relatively weak mechanical strength, Zn is widely Nanocomposite Using Cold Compaction used as an alloy addition [11] and coating material in galvaniza- tion [12] but not much for load-bearing structures [13]. It has been Followed by Melting a long standing challenge to enhance the mechanical strength of zinc toward a prominent material with a combination of high Injoo Hwang strength, high corrosion resistivity and great biocompatibility. A great deal of studies have been conducted to improve the mechan- Department of Mechanical and Aerospace Engineering, ical properties of Zn for applications such as load-bearing stents University of California, Los Angeles, [4,14]. Los Angeles, CA 90095 Since conventional manufacturing processes (e.g., alloying) e-mail: [email protected] have already reached their limits to improve mechanical proper- ties of Zn [12], innovative methods have been applied to tackle

Zeyi Guan this problem. For example, nanoparticles have been introduced to Downloaded from http://asmedigitalcollection.asme.org/manufacturingscience/article-pdf/140/8/084503/6406225/manu_140_08_084503.pdf by guest on 02 October 2021 Department of Mechanical and Aerospace Engineering, Zn to improve its properties [15]. According to the research on ceramic nanoparticle-reinforced metal matrix nanocomposites University of California, Los Angeles, recently [16–20], ceramic nanoparticles were able to improve the Los Angeles, CA 90095 mechanical strength, not only by the intrinsic high mechanical e-mail: [email protected] strength but also by the grain refinement, which introduces more grain boundaries to impede the movement of dislocations. Addi- Xiaochun Li1 tionally, the high-temperature thermal stability and chemical Fellow ASME stability of ceramic nanoparticles can also avoid nanoparticle sin- Department of Mechanical and Aerospace Engineering, tering and chemical reactions with the metal matrix during fabri- cation and processing [21,22]. One of the most important University of California, Los Angeles, problems prohibiting nanocomposites from mass production is Los Angeles, CA 90095 often the low wettability between nanoparticle and metal matrix, e-mail: [email protected] where high surface tension of metals hinders nanoparticles incor- poration and homogeneous dispersion in scalable methods such as casting [23–25]. Such nanoparticles agglomeration results in the formation of nanoparticle clusters, so that the advanced properties Zinc (Zn) is an important material for numerous applications could not be achieved [26,27]. Innovative methods, such as ultra- since it has pre-eminent ductility and high ultimate tensile strain, sonic cavitation-based process, molten salt-assisted incorporation, as well high corrosion resistivity and good biocompatibility. How- and stir casting [17,28,29], have been used to overcome the incor- ever, since Zn suffers from low mechanical strengths, most of the poration and dispersion problems with promising results to some applications would use Zn as a coating or alloying element. In extent. this study, a new class of Zn-based material with a significantly In this study, high-density and uniformly dispersed tungsten enhanced mechanical property is developed. The zinc-10 vol % carbide (WC) nanoparticles were used to enhance mechanical tungsten carbide (Zn-10WC) nanocomposite was fabricated by properties of Zn. More specifically, Zn-10 vol % WC (Zn-10WC cold compaction followed by a melting process. The Zn-10WC thereafter) nanocomposites were fabricated by cold compaction nanocomposites offer a uniform nanoparticle dispersion with little followed by a melting process to obtain a more uniform dispersion agglomeration, exhibiting significantly enhanced mechanical of nanoparticles. This is a promising method for scalable manu- properties by micropillar compression tests and microwire tensile facturing of Zn matrix nanocomposite with homogeneously dis- testing. The nanocomposites offer an over 200% and 180% persed nanoparticles. Furthermore, no significant acute toxicity of increase in yield strength and ultimate tensile strength (UTS), WC nanoparticles has been reported yet regarding to its biocom- respectively. The strengthening effect could be attributed to Oro- patibility [30]. Thus, Zn-10WC microwires, which have potential wan strengthening and grain refinement induced by nanoparticles. for weaving of biomedical stents, were also fabricated by thermal [DOI: 10.1115/1.4040026] fiber drawing and mechanically tested.

2 Methods and Experimental Results

1 Introduction 2.1 Fabrication of Zn–WC Nanocomposites. Zn–WC nano- compositeswerefabricatedbycoldcompactionfollowedbya Zinc has been widely used in automotive, construction, and bio- melting process. The schematic of the experimental setup is medical industries due to its high corrosion resistance and good shown in Fig. 1. A 90% volume fraction of Zn micropowders biocompatibility [1–5]. More specifically, Zn-based alloys are (150 lm, Goodfellow) and a 10% volume fraction of WC nano- commonly used in many applications such as an anticorrosion particles (150 nm, U.S. Research Nanomaterials, Inc., Houston, agent and galvanization due to its high corrosion resistance. TX) were weighted and mixed. The powder mixture were Magnesium additions improve the corrosion resistance of zinc- blended by a mechanical shaker (SK-O330-Pro) at 300 RPM aluminum alloy galvanized steel [6], in which the chemical resis- for 30 min. The well-blended Zn–WC powder mixture was tivity was enhanced by fast cooling rate, such that small grain size added to a cylindrical stainless steel mold (inner diameter: 19 of the primary Zn dendrites was obtained [7]. The good biocom- mm) for cold compaction into a pellet using a hydraulic press patibility of Zn has broaden its applications to the biomedical field under 85 kN at room temperature. The Zn–WC pellet was such as orthopedic implants and tissue generations [8,9]. The ideal melted with manual stirring in an alumina crucible at the tem- corrosion rate of Zn in human body recently makes it a good perature of 450 C by an electrical resistance furnace under a protection gas of Argon (Ar) for 30 min. This additional melting process aims at eliminating porosity and promoting the nano- particle dispersion. The final product was cooled down under 1Corresponding author. Manuscript received January 4, 2018; final manuscript received April 13, 2018; Ar gas protection. Pure Zn sample was also manufactured in published online May 21, 2018. Assoc. Editor: Donggang Yao. the same conditions as reference.

Journal of Manufacturing Science and Engineering AUGUST 2018, Vol. 140 / 084503-1 Copyright VC 2018 by ASME Fig. 1 Schematic of experimental method Downloaded from http://asmedigitalcollection.asme.org/manufacturingscience/article-pdf/140/8/084503/6406225/manu_140_08_084503.pdf by guest on 02 October 2021

2.2 Microstructure Characterization and Nano-Indentation analysis. The samples went through grinding and polishing (Allied of Zn–WC Nanocomposites. The Zn-10WC nanocomposite sam- M-Prep 5TM Grinder/Polisher) with a colloidal silica suspension ples were characterized by scanning electron microscope (SEM) of 0.5 lm and 0.02 lm, followed by an extra surface cleaning for microstructure analysis and by energy dispersive X-ray spec- processing by a low-angle ion milling (4 deg, 3.25 keV with troscope (EDS) for quantitative element detection and dispersion 10 lA) for 2 h. Figures 2(a)–2(c) showed the uniformly

Fig. 2 (a)–(c) Microstructure of Zn-10WC nanocomposite by SEM with different magnifica- tion. (d)–(g) EDS detection of elements Zn, W, and O, indication Zn matrix, WC nanoparticles, and oxidations. (h) and (i) Grain size of Zn and Zn-10 vol % WC microstructure by SEM.

084503-2 / Vol. 140, AUGUST 2018 Transactions of the ASME Table 1 Elastic moduli of pure Zn and Zn-10WC nano- 2.3 Zn–WC Nanocomposite Micropillar Compression Test composites for Yield Strength Measurement. In addition to study the mechanical strength, Zn-10WC nanocomposites were character- Samples Pure Zn (GPa) Zn-10WC (GPa) ized by the microcompression tests using a nanoindenter (MTS Nano Indenter XP) with a 10 lm diameter-flat punch. Focus ion- 1 62.2 102.9 2 55.6 100.6 beam (FEI Nova 600 Nanolab Dual-Beam FIB–SEM) was used to 3 67.5 112.5 machine micropillars of 10 lm in height and 3.5 lm in diameter 4 66.4 94.5 on nanocomposites samples and reference samples in Figs. 3(a) 5 70.4 101.6 and 3(b), respectively. The results showed that nanocomposite Average 64.4 102.4 micropillars have a uniform and dense nanoparticle dispersion on Standard deviation 5.1 5.8 the surface. The compression data were shown in Fig. 3(c), where Zn–WC samples obtained significantly higher yield strength (118 MPa), more than five times higher than the pure Zn sample distributed 10 vol % WC nanoparticles in Zn matrix. The rela- (22 MPa). Table 2 shows the yield and ultimate compressive Downloaded from http://asmedigitalcollection.asme.org/manufacturingscience/article-pdf/140/8/084503/6406225/manu_140_08_084503.pdf by guest on 02 October 2021 tively bright- and dark-phase areas corresponded to WC nanopar- strength of the pure Zn and Zn-10WC nanocomposites in the com- ticles and Zn matrix, respectively. The microstructure of Zn–WC pression tests. The yield strength of the pure Zn and Zn-10WC nanocomposite suggests that WC nanoparticles were separated by nanocomposites are 23.463.6 MPa and 116.4620 MPa, respec- Zn of a few tens of nanometers. Energy dispersive X-ray spectro- tively. The average ultimate compressive strength of pure Zn and scope characterization indicates that the nanocomposite sample Zn-10WC are 51 MPa and 507 MPa. It is clear that WC nanopar- consists of zinc (77.6 wt %), tungsten (20.2 wt %), and oxygen ticles significantly enhanced the mechanical strength of Zn. (2.2 wt %), as shown in Figs. 2(d)–2(g). Highly concentrated tung- sten carbide was detected in such sample, with an equivalent to 2.4 Tensile Testing Using Zn–WC Nanocomposites Micro- 11.2 vol %, which is within an acceptable error range due to the wires. Zn-10WC nanocomposite microwires were fabricated by inaccuracy of the testing machine, implying that WC nanopar- thermal fiber drawing method [31], while using borosilicate glass ticles were fully incorporated into Zn. The average grain size of tubing (inner diameter: 1.0 mm, and outer diameter: 6.5 mm) as pure Zn and Zn–WC nanocomposites were also measured to be the cladding material. The nanocomposite wires could serve as approximately 16.9–4.28 lm, respectively, as shown in Figs. 2(h) the starting materials for stent fabrication. The nanocomposite and 2(i). preform was thermally drawn at 820 C (feeding speed: 100 lm/s, Nano-indentation tests were performed to measure the elastic and pulling speed: 2.5 mm/s) to obtain Zn–WC microwires of moduli of pure Zn and Zn-10WC nanocomposite using a nano- 200 lm in diameter with a draw-down ratio of 25. The glass clad- indenter (MTS Nano Indenter XP) with a Berkovich tip (20 nm ding was etched out by 49% aqueous hydrofluoric acid to the clad- radius, diamond). Table 1 presents that the elastic moduli of ding thickness of 0.1 mm, whereas the remaining glass shell was pure Zn and Zn-10WC nanocomposites are 64.468.8 GPa and manually removed. 102.4610.1 GPa, respectively. It is clear that the WC nanopar- The Zn-10WC nanocomposite microwires were then tensile ticles improved the elastic modulus of pure Zn significantly. tested using a dynamic mechanical analyzer (Q 800 DMA, TA

Fig. 3 Zn and Zn-10WC micropillars and their corresponding micropillar compression test results

Journal of Manufacturing Science and Engineering AUGUST 2018, Vol. 140 / 084503-3 Table 2 Yield strength and ultimate tensile strength of pure Zn and Zn-10WC nanocomposite

Pure Zn Zn-10WC

Samples Yield strength (MPa) Ultimate compressive strength (MPa) Yield strength (MPa) Ultimate compressive strength (MPa)

1 21 56 136 547 2 24 50 102 480 3 22 51 118 601 4 23 45 117 406 5 27 53 109 502 Average 23.4 51.0 116.4 507.2 Standard deviation 2.1 3.6 11.4 65.4 Downloaded from http://asmedigitalcollection.asme.org/manufacturingscience/article-pdf/140/8/084503/6406225/manu_140_08_084503.pdf by guest on 02 October 2021

Fig. 4 (a) Zn-10WC microwire tensile testing setup, (b) tensile testing result of stress–strain curve for Zn-10WC and pure Zn. (c)–(e) SEM images of microwire samples, with nanoparticles on the surface. (f) Longitudinal cross section image of Zn-10WC microwire with well- distributed WC nanoparticles. instruments). The result of the stress–strain curves were obtained molten Zn infiltrated into the nanoscale gaps among WC nano- for both nanocomposite and pure zinc microwires, as shown in particles, preventing the nanoparticles agglomeration. WC Figs. 4(a) and 4(b). The pure Zn wires obtained a ultimate tensile nanoparticles in a molten Zn are then dispersed and stabilized strength (UTS) of 37 MPa, yield strength of 18 MPa, and ultimate by a thermally activated dispersion mechanism recently discov- tensile strain of 35.1%, while Zn-10WC nanocomposite micro- ered [20]. Furthermore, microstructure characterization, nano- wires exhibited an UTS of 103 MPa, yield strength of 55 MPa, indentation tests, micropillar compression tests, and microwire and ultimate tensile strain of 5.0%. Table 3 presents the yield and tensile tests were performed. ultimate tensile strength of the pure Zn and Zn-10WC nanocom- The mechanical properties of the Zn–WC nanocomposites were posites in the tensile test. The yield strength of the pure Zn and substantially enhanced for two major reasons: Orowan strengthen- Zn-10WC nanocomposite are 13.464.6 MPa and 54.868.8 MPa, ing and grain refinement. WC intrinsically offers a high hardness respectively. The average ultimate tensile strength of pure Zn and of 2600 HV and an ultimate compression strength of 2.7 GPa [32]. Zn-10WC nanocomposites are 27 MPa and 102 MPa. Further veri- This Orowan strengthening by WC nanoparticles could be gener- fication of WC nanoparticle dispersion in the microwires were ally determined by obtained through SEM by inspecting the microwire surface and  longitudinal cross section, as shown in Figs. 4(c)–4(f). 1=3 uGmb 6Vp DrOrowan ¼ (1) dp p 3 Discussion

Zn-10WC nanocomposites were successfully fabricated by cold where u is a constant equal to 2, Gm is the shear modulus of Zn, b compaction followed by a melting process. The method was is the Burgers vector, Vp is the volume fraction, and dp is the able to efficiently incorporate WC nanoparticles into Zn while reinforcement size [33]. With a rough estimation assuming per- avoiding potential oxidation problem. During the melting process, fectly homogeneous dispersion, and Gm ¼ 43 GPa; Vp ¼ 10%;

084503-4 / Vol. 140, AUGUST 2018 Transactions of the ASME Table 3 Yield and ultimate tensile strength of the pure Zn and Zn-10WC nanocomposites microwires

Pure Zn Zn-10WC

Samples Yield strength (MPa) Ultimate tensile strength (MPa) Yield strength (MPa) Ultimate tensile strength (MPa)

1 183757108 2 11214682 3 173559110 4 9 17 57 107 5 122655103 Average 13.4 27.2 54.8 102 Standard deviation 3.5 7.8 4.6 10.3 Downloaded from http://asmedigitalcollection.asme.org/manufacturingscience/article-pdf/140/8/084503/6406225/manu_140_08_084503.pdf by guest on 02 October 2021

b ¼ 0:27 nm; dp ¼ 200 nm; u ¼ 2, the strengthening could be Funding Data determined to be DrOrowan ¼ 66:9 MPa. Further strengthening could also be contributed to the grain Division of Civil, Mechanical and Manufacturing Innova- refinement due to fact that nanoparticle impeded the solidification tion (1449395). front. The average grain size of the Zn–WC nanocomposite was refined from 16.9 lm to 4.28 lm. The grain refinement could enhance the mechanical strength through the grain boundary strengthening, as known as Hall–Petch strengthening, correspond- References ing to the equation [1] Short, N., and Dennis, J., 1997, “Corrosion Resistance of Zinc-Alloy Coated Steel in Construction Industry Environments,” Trans. IMF, 75(2), pp. 1=2 47–52. Dry ¼ kd (2) [2] Wilcox, G., and Gabe, D., 1993, “Electrodeposited Zinc Alloy Coatings,” Cor- ros. Sci., 35(5–8), pp. 1251–1258. [3] Jun, B., Yun, Z., Liu, X.-H., and Wang, G.-D., 2006, “Development of Hot Dip where Dry is the yield strength, k is the strengthening coefficient Galvanized Steel Strip and Its Application in Automobile Industry,” J. Iron 1=2 (kZn ¼ 0:22 MPa m ) and d is the grain size. Dry is roughly cal- Steel Res., Int., 13(3), pp. 47–50. culated to be 52.8 MPa based on the equation. It should be noted [4] Bowen, P. K., Drelich, J., and Goldman, J., 2013, “Zinc Exhibits Ideal Physio- logical Corrosion Behavior for Bioabsorbable Stents,” Adv. Mater., 25(18), pp. that the theoretical predictions do not match the experimental 2577–2582. results exactly, possibly due to defects and nonideal nanoparticle [5] Short, N. R., and Dennis, J. K., 2017, “Corrosion Resistance of Zinc-Alloy dispersion. Coated Steel in Construction Industry Environments,” Trans. IMF, 75(2), pp. Although promising results have been shown in this work, a 47–52. [6] Elvins, J., Spittle, J. A., Sullivan, J. H., and Worsley, D. A., 2008, “The Effect few factors needed to be considered to account for variation of of Magnesium Additions on the Microstructure and Cut Edge Corrosion Resist- results and error. Stress concentrations and crack propagations ance of Zinc Aluminium Alloy Galvanised Steel,” Corros. Sci., 50(6), pp. can occur at the micro/nanoscale porosities formed in material 1650–1658. processing. Surface defects (notches and dimples) on the micro- [7] Elvins, J., Spittle, J. A., and Worsley, D. A., 2005, “Microstructural Changes in Zinc Aluminium Alloy Galvanising as a Function of Processing Parameters and wires that were created during the glass removal process could Their Influence on Corrosion,” Corros. Sci., 47(11), pp. 2740–2759. lead to a stress concentration. The residual stress or defects by the [8] Staiger, M. P., Pietak, A. M., Huadmai, J., and Dias, G., 2006, “Magnesium and clamp in the DMA tensile machine might also induce a reduction Its Alloys as Orthopedic Biomaterials: A Review,” Biomaterials, 27(9), pp. in the strength of microwires under testing. In addition, the pillar 1728–1734. [9] Ma, J., Zhao, N., and Zhu, D., 2016, “Bioabsorbable Zinc Ion Induced Biphasic size (3.5 lm in diameter) in the microcompression test is closed to Cellular Responses in Vascular Smooth Muscle Cells,” Sci. Rep., 6(1), 2 lm in the average grain size of Zn in the Zn-10WC nanocompo- p. 26661. site, which affect the strength of the Zn-10WC nanocomposite. [10] Bowen, P. K., Shearier, E. R., Zhao, S., Guillory, R. J., Zhao, F., Goldman, J., and Drelich, J. W., 2016, “Biodegradable Metals for Cardiovascular Stents: From Clinical Concerns to Recent Zn-Alloys,” Adv. Healthcare Mater., 5(10), 4 Conclusions pp. 1121–1140. [11] Chen, D., He, Y., Tao, H., Zhang, Y., Jiang, Y., Zhang, X., and Zhang, S., In summary, Zn–WC nanocomposite with a high volume frac- 2011, “Biocompatibility of Magnesium-Zinc Alloy in Biodegradable Orthope- tion of WC nanoparticles has been successfully fabricated by cold dic Implants,” Int. J. Mol. Med., 28(3), pp. 343–348. compaction followed by a melting process. Zn–WC nanocompo- [12] Meyers, M. A., Mishra, A., and Benson, D. J., 2006, “Mechanical Properties of Nanocrystalline Materials,” Prog. Mater. Sci., 51(4), pp. 427–556. site microwires were fabricated by thermal fiber drawing so that [13] Economides, N., Kotsaki-Kovatsi, V.-P., Poulopoulos, A., Kolokuris, I., Rozos, they could be used for stent weaving. WC nanoparticles were well G., and Shore, R., 1995, “Experimental Study of the Biocompatibility of Four dispersed and distributed in the Zn matrix. Zn–WC nanocompo- Root Canal Sealers and Their Influence on the Zinc and Calcium Content of sites offer significantly enhanced mechanical properties, mostly Several Tissues,” J. Endod., 21(3), pp. 122–127. [14] Yang, H., Wang, C., Liu, C., Chen, H., Wu, Y., Han, J., Jia, Z., Lin, W., Zhang, due to Orowan strengthening and grain refinement. Due to D., and Li, W., 2017, “Evolution of the Degradation Mechanism of Pure Zinc surface defects after the glass removing process and some micro/ Stent in the One-Year Study of Rabbit Abdominal Aorta Model,” Biomaterials, nanoporosities in the Zn-10WC microwires, the tensile testing 145, pp. 92–105. results do not meet the theoretical expectation well. Further study [15] Mortensen, A., and Llorca, J., 2010, “Metal Matrix Composites,” Annu. Rev. Mater. Res., 40(1), pp. 243–270. is needed. Zn–WC nanocomposite with high mechanical proper- [16] Javadi, A., Cao, C., and Li, X., 2017, “Manufacturing of Al-TiB2 Nanocompo- ties can open-up exciting new applications. sites by Flux-Assisted Liquid State Processing,” Procedia Manuf., 10, pp. 531–535. [17] Liu, W., Cao, C., Xu, J., Wang, X., and Li, X., 2016, “Molten Salt Assisted Acknowledgment Solidification Nanoprocessing of Al-TiC Nanocomposites,” Mater. Lett., 185, pp. 392–395. This work was partially support by National Science Founda- [18] Xu, J., Chen, L., Choi, H., Konish, H., and Li, X., 2013, “Assembly of Metals tion. We thank A. Javadi at University of California, Los Angeles and Nanoparticles Into Novel Nanocomposite Superstructures,” Sci. Rep., 3(1), p. 1730. for his help with the discussion in nanocomposite fabrication. We [19] Xu, J., Chen, L., Choi, H., and Li, X., 2012, “Theoretical Study and Pathways also thank C. Linsley at University of California, Los Angeles, for for Nanoparticle Capture During Solidification of Metal Melt,” J. Phys.: Con- his help with tensile testing. dens. Matter, 24(25), p. 255304.

Journal of Manufacturing Science and Engineering AUGUST 2018, Vol. 140 / 084503-5 [20] Chen, L.-Y., Xu, J.-Q., Choi, H., Pozuelo, M., Ma, X., Bhowmick, S., Yang, [27] Tjong, S. C., 2007, “Novel Nanoparticle-Reinforced Metal Matrix J.-M., Mathaudhu, S., and Li, X.-C., 2015, “Processing and Properties of Mag- Composites With Enhanced Mechanical Properties,” Adv. Eng. Mater., 9(8), nesium Containing a Dense Uniform Dispersion of Nanoparticles,” Nature, pp. 639–652. 528(7583), pp. 539–543. [28] Li, X., Yang, Y., and Cheng, X., 2004, “Ultrasonic-Assisted Fabrication of [21] Stefanescu, D., Dhindaw, B., Kacar, S., and Moitra, A., 1988, “Behavior of Metal Matrix Nanocomposites,” J. Mater. Sci., 39(9), pp. 3211–3212. Ceramic Particles at the Solid-Liquid Metal Interface in Metal Matrix [29] Lan, J., Yang, Y., and Li, X., 2004, “Microstructure and Microhardness of SiC Composites,” Metall. Trans. A, 19(11), pp. 2847–2855. Nanoparticles Reinforced Magnesium Composites Fabricated by Ultrasonic [22] Bolton, J., and Gant, A., 1993, “Phase Reactions and Chemical Stability of Method,” Mater. Sci. Eng.: A, 386(1–2), pp. 284–290. Ceramic Carbide and Solid Lubricant Particulate Additions Within Sintered [30] Bastian, S., Busch, W., Kuhnel,€ D., Springer, A., Meißner, T., Holke, R., High Speed Steel Matrix,” Powder Metall., 36(4), pp. 267–274. Scholz, S., Iwe, M., Pompe, W., and Gelinsky, M., 2009, “Toxicity of Tungsten [23] Hashim, J., Looney, L., and Hashmi, M., 1999, “Metal Matrix Composites: Pro- Carbide and Cobalt-Doped Tungsten Carbide Nanoparticles in Mammalian duction by the Stir Casting Method,” J. Mater. Process. Technol., 92–93, pp. 1–7. Cells In Vitro,” Environ. Health Perspect., 117(4), pp. 530–536. [24] Hashim, J., Looney, L., and Hashmi, M., 2002, “Particle Distribution in Cast Metal [31] Zhao, J., Javadi, A., Lin, T.-C., Hwang, I., Yang, Y., Guan, Z., and Li, X., Matrix Composites—Part I,” J. Mater. Process. Technol., 123(2), pp. 251–257. 2016, “Scalable Manufacturing of Metal Nanoparticles by Thermal Fiber [25] Hashim, J., Looney, L., and Hashmi, M., 2002, “Particle Distribution in Cast Drawing,” ASME J. Micro- Nano-Manuf., 4(4), p. 041002. Metal Matrix Composites—Part II,” J. Mater. Process. Technol., 123(2), pp. [32] Kurlov, A. S., and Gusev, A. I., 2013, “Nanocrystalline Tungsten Carbide,” 258–263. Tungsten Carbides, Springer, Cham, Switzerland, pp. 109–189. [26] Pagounis, E., and Lindroos, V., 1998, “Processing and Properties of Particulate [33] Liu, G., Zhang, G., Jiang, F., Ding, X., Sun, Y., Sun, J., and Ma, E., 2013, Downloaded from http://asmedigitalcollection.asme.org/manufacturingscience/article-pdf/140/8/084503/6406225/manu_140_08_084503.pdf by guest on 02 October 2021 Reinforced Steel Matrix Composites,” Mater. Sci. Eng.: A, 246(1–2), pp. “Nanostructured High-Strength Molybdenum Alloys With Unprecedented Ten- 221–234. sile Ductility,” Nat. Mater., 12(4), pp. 344–350.

084503-6 / Vol. 140, AUGUST 2018 Transactions of the ASME