Microstructure and properties of W-15Cu alloys prepared by mechanical alloying and spark plasma sintering process

Abstract

W-15Cu composite powders prepared by mechanical alloying (MA) of raw powders were consolidated by spark plasma sintering (SPS) process at temperature ranged 1 230–1 300 °C for 10 min and under a pressure of 30 MPa. By using high energy milling, particles containing very fine tungsten grains embedded in copper, called composite particles, could be produced. The W grains were homogeneously dispersed in copper phase, which was very important to obtain W-Cu alloy with high mechanical properties, fine and homogeneous microstructure. The microstructure and properties of W-15Cu alloys prepared by SPS processes at different temperature were researched. The results show that W-15Cu alloys consolidated by SPS can reach 99.6 % relative density, and transverse rupture strength (TRS) is 1 400.9 MPa, Rockwell C hardness (HRC) is 45.2, the thermal conductivity is 196 W/m·K at room temperature, the average grain size is less than 2 μm, and W-15Cu alloy with excellent properties, homogeneous and fine microstructure is obtained.

Keywords

W-15Cu / mechanical alloying / spark plasma sintering (SPS)

References

[1] Kim Y. D., Oh N. L., Oh S. T., . Thermal Conductivity of W-Cu Composites at Various Temperatures[J]. Materials Letters, 2001, 51(5): 420-424.

[2] Yoon E. S., Lee J. S., Oh S. T., . Microstructure and Sintering Behavior of W-Cu Nanocomposite Powder Produced by Thermo-chemical Process[J]. Int. J.Ref. Met. Hard Mater., 2002, 20(3): 201-206.

[3] Hong S. H., Kim B. K. Fabrication of W-20 wt % Cu Composite Nanopowder and Sintered Alloy with High Thermal Conductivity[J]. Materials Letters, 2003, 57(18): 2 761-2 767.

[4] Ryu S. S., Kim Y. D., Moon I. H. Dilatometric Analysis on the Sintering Behavior of Nanocrystalline W-Cu Prepared by Mechanical Alloying[J]. Journal of Alloys and Compounds, 2002, 335(1–2): 233-240.

[5] Kim D. G., Kim G. S., Oh S. T., . The Initial Stage of Sintering for the W-Cu Nanocomposite Powder Prepared from W-CuO Mixture[J]. Materials Letters, 2004, 58(5): 578-581.

[6] Doré F., Lay S., Eustathopoulos N., . Segregation of Fe During the Sintering of Doped W-Cu Alloys[J]. Scripta Materialia, 2003, 49(3): 237-242.

[7] Kim D. G., Lee K. W., Oh S. T., . Preparation of W-Cu Nanocomposite Powder by Hydrogen-reduction of Ball-milled W and CuO Powder Mixture[J]. Materials Letters, 2004, 58(7–8): 1 199-1 203.

[8] Franciné Alves da Costa, Angelus Giuseppe Pereira da Silva Uilame Umbelino Gomes. The Influence of the Dispersion Technique on the Characteristics of the W-Cu Powders and on the Sintering Behavior[J]. Powder Technol., 2003, 134(1–2): 123-132.

[9] Kim J. C., Moon I. H. Sintering of Nanostructured W-Cu Alloys Prepared by Mechanical Alloying[J]. NanoStructured Materials, 2002, 335(1–2): 283-290.

[10] Doré F., Martin C. L., Allibert C. H. Apparent Viscosity of W-Cu Powder Compacts During Sintering[J]. Mater. Sci. Eng. A, 2004, 383(2): 390-398.

[11] Cha S. I., Hong S. H., Kim B. K. Spark Plasma Sintering Behavior of Nanocrystalline WC-10Co Cemented Carbide Powders[J]. Mater. Sci. Eng. A, 2003, 351(1–2): 31-38.

[12] Gao L., Hong J. S., Miyamoto H., . Bending Strength and Microstructure of Al₂O₃ Ceramics Densified by Spark Plasma Sintering[J]. J. Eur. Ceram. Soc., 2000, 20(12): 2 149-2 152.