本研究利用霍普金森試驗機（split-Hopkinson pressure bar, SHPB）結合粉末冶金製程的優勢，探討燒結製程參數與Mo元素含量對鎢基重合金的微結構與動態性能的影響。整體研究共規劃五個影響參數，依序分別設定為固液相比、Mo元素添加量、鎳鐵重量比、燒結持溫時間、燒結方法等，透過調整各影響參數內的變數來獲得不同微結構組織之W基重合金，再利用萬能材料試驗機與動態實驗裝置分別在常溫下施以0.1s-1，1500 s-1，2200s-1，4500s-1，6500s-1，7500s-1六種不同低、中、高應變速率範圍的負載，以便對材料之動態機械性質與微結構關係進行較廣泛的分析比較。透過以上系列的研究結果顯示：W基重合金的微結構中，W晶粒尺寸、接觸性、介金屬相的析出、基地相中的溶質固溶量、及燒結密度都是影響最終機械性質重要的評估項目，適當的調整製程參數或添加其他合金元素可以有效控制微結構而獲得一定程度的動態性能提升。然而限於一般爐體加熱設備的功率限制，以傳統粉末冶金製程所進行的液相燒結方法對於微結構的控制程度還是有其侷限性，而且添加其他合金元素會增加成本與系統的複雜性，同時造成更多介金屬化合物的產生。因此除了傳統的一次燒結製程外，本研究另外嘗試以二階段燒結方法來改善微結構，實驗的方法是先藉由熱分析與燒結參數的控制使材料在固相燒結的緻密度達99%以上且不會有明顯的晶粒成長，第二階段再以高週波裝置快速加熱至1470℃並短暫持溫後直接進行急速水冷卻，由於胚體可以在很短的時間內進行液相燒結與冷卻，而可以大幅的降低W晶粒尺寸、減少高溫介金屬相的析出，同時保有低接觸性、高溶質固溶濃度的Ni-Fe-W理想基地相組織，也因此可以展現出更令人滿意的動態機械性能。

In this study, tungsten heavy alloys in the form of split-Hopkinson pressure bar, SHPB, were prepared by powder metallurgy process. The effects of five parameters on the microstructural evolution and dynamic mechanical behaviors of tungsten heavy alloys were investigated, including tungsten volume fraction, molybdenum addition, nickel to iron weight ratio, isothermal hold time at the sintering temperature, and sintering route. By using a universal material testing machine and a dynamic test device, the sintered specimens were tested under six strain rates (0.1s-1, 1500 s-1, 2200 s-1, 4500 s-1, 6500 s-1, 7500 s-1) to examine their dynamic mechanical behaviors. The mechanical behaviors were closely related to the details of the microstructure, including tungsten grain size, contiguity of tungsten grains, precipitation of intermetallic phases, dissolved concentration of solute in the matrix phase, and sintered density. The appropriate adjustment of processing parameters or the addition of alloy elements could be effective in controlling the sintered microstructure and, therefore, promoting dynamic mechanical properties to some extent. However, the limitation of the power efficiency of typical sintering furnaces led to some limitations on the control of microstructures in a liquid phase sintering process, while the addition of other alloy elements could either increase the cost to the alloys or could cause the precipitation of intermetallic com-pounds. Therefore, in addition to the traditional sintering process, a two-stage sintering practice to improve the microstructure was illustrated. The two-stage sintering practice included first sintering the alloys by solid phase sintering, reaching a sintered density of about 99% theoretical and no obvious grain growth, and subsequently fast sintering the alloys by induction heating to the formation of a liquid phase at 1470 ℃ , with a short isothermal hold and then water quenched. In the secondary liquid phase sintering stage, the alloys could be completely densified and the contiguity of grains could be substantially reduced, with minimal grain growth, while a high dissolved concentration of W in the matrix phase could be maintained and the precipitation of intermetallic phase could be avoided. All of these beneficial consequences led to more satisfactory dynamic mechanical behaviors.

1.B. C. Muddle, “Interphase Boundary Precipitation in Liquid Phase Sintered W-Ni-Fe and W-Ni-Cu Alloys”, Metallurgical Transactions A, vol. 15A, pp. 1089-1098, 1984.
2.B. C. Muddle and D.V. Edmonds, “Precipitation in a Liquid Phase Sintered W-Ni-Fe Alloy”, Acta Metall., vol. 33, pp. 2119-2128, 1985.
3.B. H. Rabin and R.M. German, “Microstructure Effect on Tensile Properties of Tungsten-Nickel-Iron Composites”, Metallurgical Transactions A, vol. 19A, pp. 1523-1531, 1988.
4.A. Bose and R.M. German, “Sintering Atmosphere Effects on Tensile Properties of Heavy Alloys”, Metallurgical Transactions A, vol. 19A, pp. 2467-2475, 1988.
5.A. Bose and R. M. German, “Matrix Composition Effect on the Tensile Properties of Tungsten-Molybdenum Heavy Alloys”, Metallurgical Transactions A, vol. 21A, pp. 1325-1327, 1990.
6.R. M. German, “Critical Developments in Tungsten Heavy Alloys”, Tungsten & Tungsten Alloys - 1992, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 3-12, 1992.
7.S. Lee and Jr. Magness, “Properties and Performance of KE Penetrator Materials”, Tungsten & Tungsten Alloys - 1992, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 15-22, 1992.
8.P. Woolsey, R. J. Dowding, K. J. Tauer and F. H. Hodi, ”Perfor-mance-Property Relationships in Tungsten Alloys Penetrators”, Tungsten & Tungsten Alloys - 1992, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 533-540, 1992.
9.M. Nakai and N. Okato, “The Effect of Cooling Rate on Ductility of Tungsten Heavy Alloys”, Advances in Powder Metallurgy & Particulate Materials - 1992 vol. 3, Compiled by J. M. Capus and R. M. German, Metal Powder Industries Federation, Princeton, New Jersey, pp. 259-266, 1992.
10.R. M. German, A. Bose and S. S. Mani, “Sintering Time and Atomsphere Influences on the Microstructure and Mechanical Properties of Tungsten Heavy Alloys”, Metallurgical Transactions A, vol. 23A, pp. 211-219, 1992.
11.J. R. Spencer and J. A. Mullendore, “The Effect of Nickel: Iron Ratios on the Mechanical Properties, Microstructure and Processing of W-Ni-Fe Alloys”, Tungsten & Tungsten Alloys - 1992, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 111-118, 1992.
12.A. Belhadjhamida and R.M. German, “ The Processing of W-Ni-Mn Alloys and their Mechanical Properties”, Advances in Powder Metallurgy & Particulate Materials - 1993 vol. 2, Compiled by A. Lawley and A. Swanson, Metal Powder Industries Federation, Princeton, New Jersey, pp. 227-232, 1993.
13.R. J. Dowding and Martin G. H. Wells, “Army P/M Research Development Overview”, P/M in Aerospace, Defense and Demanding Applications - 1993, Edit by F. H. Fores, Metal Powder Industries Federation, Princeton, New Jersey, pp. 25-37, 1993.
14.J. R. Spencer, “Effect of Composition, Impurities, and Processing on the Properties of Tungsten Heavy Alloys”, Tungsten and Refractory Metals 3 - 1995, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 183-190, 1995.
15.J. Dasa, G. Appa Raoa, S. K. Pabib, Microstructure and mechanical properties of tungsten heavy alloys, Materials Science and Engineering A 527, pp. 7841-7847, 2010.
16.J. Dasa, G. Appa Raoa, S. K. Pabib, M. Sankaranarayanaa, Bijoy Sarmaa, “Deformation behaviour of a newer tungsten heavy alloy”, Materials Science and Engineering A 528, pp.6235- 6247, 2011.
17.S. Yadav, K. T. Ramesh, “The mechanical properties of tungsten-based composites at very high strain rates”, Materials Science and Engineering A203, pp. 140-153, 1995.
18.D. K. Kim, S. Lee, W. H. Baek, “Microstructural study of adiabatic shear bands formed by high-speed impact in a tungsten heavy alloy penetrator”, Materials Science and Engineering A249, pp. 197-205, 1998.
19.W. S. Lee, G. L. Xiea, C. F. Lin, “The strain rate and temperature dependence of the dynamic impact response of tungsten composite”, Materials Science and Engineering A257, pp.256–267, 1998.
20.Z. Wei, J. Yu, S. Hu, Y. Li, “Infuence of microstructure on adiabatic shear localization of pre-twisted tungsten heavy alloys”, International Journal of Impact Engineering 24, pp.747-758, 2000.
21.黃坤祥， 粉末冶金學， 中華民國粉末冶金協會，pp. 5,129,315-318, 2001。
22.馮慶芬， 粉末冶金學， 新文京出版公司，pp.6-7, 2002。
23.R. M. German, Liquid Phase Sintering, Plenum Press, New York, pp. 1-12, 54, 92, 139, 1985.
24.C. L. Briant, “Tungsten: Properties, Processing, and Applications”, Advanced Materials & Processes, vol. 11, pp. 29-32, 1998.
25.J. K. Park, S-J. Kang, K. Y. Eun and D. N. Yoon, “Microstructural Change During Liquid Phase Sintering of W-Ni-Fe Alloy”, Metallurgical Transactions A, vol. 20A, pp. 837-845, 1989.
26.ASM Handbook, Alloy phase Diagrams, Vol. 3, ASM International, 2‧206, 2‧320, 3‧55.
27.J. K. Park, S-J. Kang, K. Y. Eun and D. N. Yoon, “Microstructural Change During Liquid Phase Sintering of W-Ni-Fe Alloy”, Metallurgical Transactions A, vol. 20A, pp. 837-845, 1989.
28.P. B. Kemp and R. M. German, “Grain growth in liquid-phase-sintered W-Mo-Ni-Fe alloys”, Jounal of the Less-Common Metals, 175, pp. 353-368, 1991.
29.T. Y. Chan and S. T. Lin, “Microstructure evolution on sintered properties of W-8 pct Mo-7 pct Ni-3 pct Fe alloy”, Jounal of Materials Science, 35, pp.3759-3765, 2000.
30.G. C. Wu, Q. You, D. Wang, “Influence of the addition of Lanthnum on a W-Mo-Ni-Fe heavy alloy”, International Journal of Refractory Metals & Hard Materials 17, pp.299-304, 1999.
31.K. H. Lin, C. S. Hsu, S. T. Lin, “Variables on the precipitation of an intermetallic phase for liquid phase sintered W-Mo-Ni-Fe heavy alloys”, International Journal of RefractoryMetals & Hard Materials, 20, pp. 401-408, 2002.
32.K. H. Lin, C. S. Hsu, S. T. Lin, “Precipitation mechanism of an MoNi type intermetallic phase in W-27.0at.%Mo-35.6at.%Ni-17.6at.%Fe”, International Journal of RefractoryMetals & Hard Materials 21, pp.125-133, 2003.
33.K. H. Lin, C. S. Hsu and S. T. Lin, “Precipitation of an Intermetallic Phase in Mo-alloyed Tungsten Heavy Alloys”, Materials Transactions, Vol. 44, pp. 1-9, 2003.
34.林舜天，金屬粉末射出成形彈頭及零件研製，聯勤204兵工廠、國立台灣工業技術學院建教合作案成果報告，中華民國82年10月。
35.C. S. Hsu, K. H. Lin, S. T. Lin, “Precipitation mechanisms of intermetallic compounds in W-Mo-Ni-Fe alloys”, International Journal of Refractory Metals & Hard Materials, 23, pp. 175-182, 2005.
36.A. Bose, G. Jerman and R. M. German, “Rhenium Alloying of Tungsten Heavy Alloys”, Powder Metallurgy International, vol. 21, pp. 9-12, 1989.
37.D. V. Edmonds and P. N. Jones, “Interfacial Embrittlement in Liq-uid-Phase Sintered Tungsten Heavy Alloys”, Metallurgical Transactions A, vol. 10A, pp.289-295, 1979.
38.S. G. Caldwell, “Variation of Ni/Fe Ratio in W-Ni-Fe Alloys: A Current Perspective”, Tungsten & Tungsten Alloys - 1992, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 89-96, 1992.
39.J. R. Spencer and J.A. Mullendore, “The Effect of Nickel: Iron Ratios on the Mechanical Properties, Microstructure and Processing of W-Ni-Fe Alloys”, Tungsten & Tungsten Alloys - 1992, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 111-118, 1992.
40.J. R. Spencer, “Effect of Composition, Impurities, and Processing on the Properties of Tungsten Heavy Alloys”, Tungsten and Refractory Metals 3, Edit by A. Bose and R.J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 183-190, 1995.
41.A. Bose and R. M. German, “Matrix Composition Effect on the Tensile Properties of Tungsten-Molybdenum Heavy Alloys”, Metallurgical Transactions A, vol. 21A, pp. 1325-1327, 1990.
42.A. Upadhyaya and R. M. German, “Gravitational Effects During Liquid Phase Sintering”, Materials Chemistry and Physicals, vol. 67, pp. 25-31, 2001.
43.R. M. German, Sintering Theory and Practice, John Wiley & Sons, Inc., New York, pp.225-312, 513, 1996.
44.T. K. Kang and D. N. Yoon, “Coarsening of Tungsten Grains in Liquid Nickel-Tungsten Matrix”, Metallurgical Transactions A, vol. 9A, pp. 433-438, 1978.
45.S. C. Yang, S. S. Mani and R. M. German, “Grain Growth Behavior in Liquid Phase Sintered Heavy Alloys”, Advances in Powder Metallurgy - 1990 vol. 1, Compiled by E. R. Andreotti and P. J. McGeehan, Metal Powder Industries Federation, Princeton, New Jersey, pp. 469-482, 1990.
46.R. M. German, “Limitations in Net Shaping by Liquid Phase Sintering”, Advances in Powder Metallurgy - 1991 vol. 4, Compiled by L. F. Pease and R. J. Sansoucy, Metal Powder Industries Federation, Princeton, New Jersey, pp. 183-195, 1991.
47.P. Lu, R. M. German and B. M. Marx, “Liquid Phase Sintering of Tungsten Heavy Alloys”, The International Journal of Powder Metallurgy, vol. 37, pp. 45-56, 2001.
48.M. Nakai and N. Okato, “The Effect of Cooling Rate on Ductility of Tungsten Heavy Alloys”, Advances in Powder Metallurgy & Particulate Materials - 1992 vol. 3, Compiled by J. M.Capus and R. M.German, Metal Powder Industries Federation, Princeton, New Jersey, pp. 259-266, 1992.
49.Z. He, T. H. Courtney, “Crystallization and thermal stability of mechanically alloyed W-Ni-Fe nancrystalline materials”, Materials Science and Engineering A315, pp. 166-173, 2001.
50.J. K. Park, S-J. Kang, K. Y. Eun and D.N. Yoon, “Microstructural Change During Liquid Phase Sintering of W-Ni-Fe Alloy”, Metallurgical Transactions A, vol. 20A, pp. 837-845, 1989.
51.A. Belhadjhamida and R.M. German, “ The Effect of Atmosphere, Temperature, and Composition on the Densification and Properties of Tungsten-Nickel-Manganese”, Advances in Powder Metallurgy & Particulate Materials – 1992, vol. 3, Compiled by J. M.Capus and R. M. German, Metal Powder Industries Federation, Princeton, New Jersey,pp. 47-55, 1992.
52.H. J. Ryu, S. H. Hong and W.H. Baek, “Mechanical alloying Process of 93W-5.6Ni-1.4Fe Tungsten Heavy Alloy”, Journal of Materials Processing Technology, vol. 63, pp. 292-297, 1997.
53.R. L. Orban, V. R. Constantinescu and R. Muresan, “Microstructure and Properties of Tungsten Heavy alloys Processed From Mechanically alloyed Powders”, Tungsten, Refractory Metals and Alloys 4 - 1998, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 349-356, 1998.
54.A. Bose and R. M. German, “Properties of Swaged and Aged Molybdenum Doped Heavy Alloys”, Modern Developments in Powder Metallurgy, Compilers by P. ULF Gummenson and D. A. Gustafson, Metal Powder Industries Federation, Princeton, New Jersey, pp. 139-153, 1988.
55.林寬弘，“Mo元素對液相燒結W-Ni-Fe重合金顯微結構影響之研究”，國立臺灣科技大學博士論文，92年1月。
56.P. B. Kemp and H. Zhang, “Additive Effect on the Microstructure and Properties of Tungsten Heavy Alloy Composites”, Advances in Powder Metallurgy – 1989, vol. 2, pp. 401-414, 1989.
57.Y. Lifu, C. Huaiqing, Q. Suwen and G. Qiuvan, “Study on Impurity Segregation in W-Ni-Fe Alloy”, Tungsten & Tungsten Alloys - 1992, Edit by A. Bose and R. J. Dowding, Metal Powder Industries Federation, Princeton, New Jersey, pp. 265-272, 1992.
58.M. E. Backman and S. A. Finnegan, “The propagation of adiabatic shear in Metallurgical Effects at High Strain Rates”, Plenum Press, New York, pp. 531-543, 1973.
59.M. A. Meyers,“Elastic Waves in Dynamics Behavior of Materials”, Jhon Wiely & Sons, pp.23-65, 1994.
60.R. D. Curran, L. Seaman and D. A. Shockey, “Linking Dynamic Fracture to Microstructural Process”, Shock Wave and High-Strain-Rate Phenomena in Metal: Concepts and Applications, pp.22-26, 1980.
61.U. S. Lindholm, “Techniques in Metals Research”, vol.5, Part1, R. F. Bunshah (ed.), Wiley-Interscience, New York, pp.199, 1971.
62.D. Klahn, A. K. Mukherjee and J. E. Dorn, “Proceedings of the 2nd International Conference on the Strength of Metals and Alloys”, vol.III, ASM, pp.951, 1970.
63.J. D. Campbell and W. G. Ferguson, “Temperature and Strain-Rate Dependence of the Shear Strength of Mild Steel”, Phil. Mag., vol.21, pp.63-82, 1970.
64.A. M. Eleiche and J. D. Campbell, “Strain-Rate Effects During Reverse Torsional Shear”, Exp. Mech., vol.16, pp.281-290, 1976.
65.J. A. Zukas, T. Nicholas, H. F. Swift, L. B. Greszczuk and D. R. Curran, “Impact Dynamics”, John Wiley & Sons, pp.287, 1981.
66.M. L. Lovato and M. G. Stout, “Compression Testing Techniques to Determine the Stress/Strain Behaviour of Metals Subject to Finite Deformation”, Metall. Trans. A, vol.23A, pp.935-951, 1992.
67.W. S. Lee, Chi-Feng Lin, Sen-Tay Chang, “Plastic flow of tungsten-based composite under hot compression”, Journal of Materials Processing Technology, 100, 123-130, 2000.
68.W. S. Lee, G. L. Xiea, C. F. Lin, “The strain rate and temperature dependence of the dynamic impact response of tungsten composite”, Materials Science and Engineering A257, 256–267, 1998.
69.X. Gong, J. L. Fan, B. Y. Huang, J. M. Tian, “Microstructure characteristics and a deformation mechanism of fine-grained tungsten heavy alloy under high strain rate compression”, Materials Science and Engineering A 527, 7565–7570, 2010.
70.H. J. Ryu, S. H. Hong and W. H. Baek, “Microstructure and mechanical properties of mechanically alloyed and solid-state sintered tungsten heavy alloys”, Material Science and Engineering, A291, pp.91-96, 2000.
71.M. L. Lovato and M. G. Stout, “Compression Testing Techniques to Determine the Stress/Strain Behaviour of Metals Subject to Finite Deformation”, Metall. Trans. A, vol.23A, pp.935-951, 1992.
72.J. C. Gelin, J. Oudin, and Y. Ravalard, “Determination of the Flow Stress-Strain Curve for Metals Form Axisymmeetric Upsetting”, J. of Mech. Work. Tech., vol.5, pp.297-308, 1981.
73.S. T. Chiou, W. C. Cheng and W. S. Lee, “Strain rate effects on the me-chanical properties of a Fe-Mn-Al alloy under dynamic deformations”, Material Science and Engineering, A 392, pp. 156-162, 2005.
74.W. S. Lee , C. F Lin and T. J. Liu, “Strain rate dependence of sintered 316L stainless steel”, Journal of Nuclear Materials, 359, pp.247-257, 2006.
75.W. S. Lee , C. F Lin and T. J. Liu, “Impact and fracture response of sintered 316L stainless steel subjected to high strain rate loading”, Materials Characterization, 58, pp.363-370, 2007.
76.林奇峰，“304不鏽鋼在未預變形及預變形條件下之高速撞擊特性與微觀組織的比較研究”，成功大學博士論文，91年6月。
77.J. D. Campbell and A. R. Dowling, “The Behaviour of Materials Sub-jected to Dynamic Incremental Shear Loading”, J. Mech. Phys. Sol., Vol. 18, pp. 43-63, 1970.
78.R. L. WOODWARD, I. G. McDONALD, A. GUNNER, “Comparative structure and physical properties of W-Ni-Fe alloys containing 95 and 25wt% tungsten”, 5, pp.413-414, 1986.
79.C. S. Hsu, S. T. Lin, “Coalescence of tungsten grains around molybdenum grains in the presence of a liquid phase”, Scripta materials 46, pp.869-873, 2002.
80.C. S. Hsu, P. C. Tsai, S. T. Lin, Metall. Mater. Trans. A, 32A, pp. 95, 2001.
81.K. H. Lin, C. S. Hsu, S. T. Lin, “Precipitation mechanism of an MoNi type intermetallic phase in W-27.0at.%Mo-35.6at.%Ni-17.6at.%Fe”, International Journal of RefractoryMetals & Hard Materials 21, pp.125-133, 2003.
82.K. H. Lin, C. S. Hsu, S. T. Lin, “Variables on the precipitation of an intermetallic phase for liquid phase sintered W-Mo-Ni-Fe heavy alloys”, International Journal of RefractoryMetals & Hard Materials, 20, pp. 401-408, 2002.
83.K. H. Lin, C. S. Hsu and S. T. Lin, “Precipitation of an Intermetallic Phase in Mo-alloyed Tungsten Heavy Alloys”, Materials Transactions, Vol. 44, pp. 1-9, 2003.
84.K. H. Lin, C. S. Hsu, S. T. Lin, “Structure analysis of the constitutional phases in liquid phase sintered W-Mo-Ni-Fe heavy alloys”, International Journal of Refractory Metals & Hard Materials 21, pp. 193-203, 2003.
85.C. S. Hsu, K. H. Lin, S. T. Lin, “Precipitation mechanisms of intermetallic compounds in W-Mo-Ni-Fe alloys”, International Journal of Refractory Metals & Hard Materials, 23, pp. 175-182, 2005.
86.A. Bose, D. M. Sims and R. M. German, "High Strength Tungsten Heavy Alloys With Molybdenum Additions", Refractory & Hard Materials, June, pp. 98-102, 1988.
87.A. H. Cottrell, “An Introduction to Metallurgy”, London: Edward Arnold, 1967.
88.T. Y. Chan, S. T. Lin, “Interfacial Reaction Controlled Reprecipitation of W Atoms in Liquid Ni-Fe-W-Mo Matrix Phase”, Metallurgical and Materials Transactions A,Vol.29,pp.2885-2892, 1997.
89.T. Y. Chan, S. T. Lin, “Effect of Microstructure on the Sintered Properties of W-8 pct Mo-7 pct Ni-3 pet Fe Alloy”, Journal of Materials Science, Vol.35, pp.3759-3765, 2000.
90.A. F. Guillermet and L. Ostlund, “Experimental and Theoretical Study of the Phase Equilibria in the Fe-Ni-W System”, Metallurgical Transactions, Vol. 17A, pp. 1921-1934, 1986.
91.A. L. Gurson, Journal of Engineering Material Technology, 2, pp. 99, 1977.
92.T. K. Kang and D.N. Yoon, “Coarsening of Tungsten Grains in Liquid Nickel- Tungsten Matrix”, Metallurgical Transactions A, vol. 9A, pp. 433-438, 1978.
93.S. C. Yang, S. S. Mani and R.M. German, “Grain Growth Behavior in Liquid Phase Sintered Heavy Alloys”, Advances in Powder Metallurgy – 1990, vol. 1,Compiled by E. R. Andreotti and P. J. McGeehan, Metal Powder Industries Federation, Princeton, New Jersey, pp. 469-482, 1990.
94.C. Zubillaga, F. Hernandez, J. J. Urcola and M. Fuentes, “Experimental analysis of Tungsten Coarsening in a Heavy Metal During Liquid Phase Sintering”, Acta Metall, vol. 37, pp.1865-1872, 1989.
95.M. F. Ashby, Phil. Mag. 18, pp. 399, 1970.
96.H. Soon, H. J. Ryu, W. H. Baek, “Matrix pools in a partially mechanically alloyed tungsten heavy alloy for localized shear deformation”, Material Science and Engineering, A 333, pp. 187-192, 2002.