Microstructure and mechanical properties of Cu/Al2O3 composite prepared by metal injection molding after mechanical alloying
HE Yi-qiang1,2, XU Hu-lin1,2, QIAN Chen-chen1, FENG Li-chao1,2, QIAO Bin1,2, SHANG Feng1,2, LI Hua-qiang1,2
1. School of Mechanical and Ocean Engineering, Huaihai Institute of Technology, Lianyungang 222005, Jiangsu, China;
2. Marine Resources Development Research Institute of Jiangsu, Lianyungang 222005, Jiangsu, China
Abstract：10%(volume fraction)Cu/Al2O3 composite was prepared by the process of mechanical alloying and powder injection molding, the effect of alloying time and sintering temperature on microstructure and properties of the composite was investigated, and toughening mechanism of the composite was analyzed. The results show that 10%Cu/Al2O3 composite with good bending strength and fracture toughness can be prepared by the process of mechanical alloying for 10h, degreasing and then sintering at 1550℃. Bending strength and fracture toughness of the composite prepared by this process are up to 532MPa and 4.97MPa·m1/2 respectively. Due to weak diffusion of solid atoms for the composite being sintered below 1550℃, and mobility of particle boundaries being higher than pore escaping rate for the composite being sintered above 1550℃, porosity of the composite increases, and which results in strength and fracture toughness decreasing. Extending alloying time brings grain refinement and strong bonding between Cu and Al2O3 which is beneficial to elevate strength and hardness of the composite, while it is harmful to fracture toughness of the composite. Cu powders dispersing in the Al2O3 matrix protect the Al2O3 grains from coarsening during sintering process. And increasing in toughness of ceramic composite can be attributed to crack bridging and crack deflection when the cracks encounter the ductile Cu.
 范景莲,刘勋,黄伯云,等. Ni、Cu-Al2O3纳米金属陶瓷粉末的热压[J]. 粉末冶金技术, 2005, 23(2):120-124. FAN J L, LIU X, HUANG B Y, et al. Hot pressing of Ni-Al2O3/Cu-Al2O3 cermet nanopowder[J]. Powder Metallurgy Technology, 2005, 23(2):120-124.
 刘向兵,贾成厂,王富祥,等. 用球化处理的粉末热压制备Cu-Al2O3复合材料[J]. 粉末冶金技术, 2007,25(2):129-134. LIU X B, JIA C C,WANG F X,et al. Cu-Al2O3 composite fabricated by hot pressing with sphericized powder[J]. Powder Metallurgy Technology, 2007,25(2):129-134.
 BAHRAINI M,WEBER L,NARCISO J,et al. Wetting in infiltra-tion of alumina particle preforms with molten copper[J]. Journal of Materials Science, 2005,40(9/10):2487-2491.
 刘惠敏,王楠,苏娟. 原位Al2O3/Al-Cu复合材料的制备与组织研究[J].材料工程, 2014(11):23-27. LIU H M,WANG N,SU J. Preparation and microstructure of in-situ Al2O3/Al-Cu composite[J]. Journal of Materials Engine-ering,2014(11):23-27.
 GERMAN R M. Divergences in global powder injection moulding[J]. Powder Injection Moulding International, 2008, 2(1):45-49.
 ZHANG S X, ONG Z Y, LI T, et al. Ceramic composite comp-onents with gradient porosity by powder injection moulding[J]. Materials & Design,2010,31(6):2897-2903.
 LIANG S H,FAN Z K,XU L,et al. Kinetic analysis on Al2O3/Cu composite prepared by mechanical activation and internal oxidation[J]. Composites Part A:Applied Science and Manufacturing,2004,35(12):1441-1446.
 RAZAVI-TOUSI S S, RAD R, SALAHI E, et al. Production of Al-20 wt.% Al2O3 composite powder using high energy milling[J]. Powder Technology, 2009, 192(3):346-351.
 ZEBARJAD S M, SAJJADI S A.Microstructure evaluation of Al-Al2O3 composite produced by mechanical alloying method[J]. Materials & Design, 2006, 27(8):684-688.
 ZHAO N, NASH P, YANG X. The effect of mechanical alloying on SiC distribution and the properties of 6061 aluminum composite[J]. Journal of Materials Processing Technology, 2005,170(3):586-592.
 ZAWRAH M F, ZAYED H A, ESSAWY R A, et al. Prepara-tion by mechanical alloying, characterization and sintering of Cu-20wt.%Al2O3 nanocomposites[J]. Materials & Design, 2013,46:485-490.
 TOUSI S S R,RAD R Y,SALAHI E,et al.Production of Al-20 wt.% Al2O3 composite powder using high energy milling[J]. Powder Technology,2009,192(3):346-351.
 ZAWRAH M F, ESSAWY R A, ZAYED H A, et al. Mech-anical alloying,sintering and characterization of Al2O3-20wt%-Cu nanocomposite[J]. Ceramics International,2014,40(1):31-38.
 陈振华. 现代粉末冶金技术[M]. 北京:化学工业出版社, 2013:245-246. CHEN Z H. Modern powder metallurgy technology[M]. Beijing:Chemical Industry Press, 2013:245-246.
 CHANDRASEKHAR S B, WAKEKAR N P, RAMAKRISH-NA M, et al. Dynamic strain ageing in fine grained Cu-1wt% Al2O3 composite processed by two step ball milling and spark plasma sintering[J]. Journal of Alloys and Compounds, 2016, 656:423-430.
 MADAVALI B, LEE J H,LEE J K,et al. Effects of atmosphere and milling time on the coarsening of copper powders during mechanical milling[J]. Powder Technology, 2014, 256:251-256.
 CAMPBELL S D, PELLETIER L B, POBER R L, et al. Dim-ensional and formation analysis of a restorative ceramic and how it works[J]. The Journal of Prosthetic Dentistry,1995,74(4):332-340.
 SHEHATA F, FATHY A, ABDELHAMEED M, et al. Prep-aration and properties of Al2O3 nanoparticle reinforced copper matrix composites by in situ processing[J]. Materials & Design,2009,30(7):2756-2762.