(1. 江蘇省海洋資源開發(fā)研究院，連云港，222005；
2. 淮海工學院 機械工程學院，連云港 222005；
3. 湖南科技大學 機電學院，湘潭 411201)
摘 要: 采用熱壓后多道次熱軋制備噴射沉積SiCp/Al-8.5Fe-1.3V-1.7Si復合材料板材，研究熱壓、軋制工藝參數(shù)對復合材料顯微組織、力學性能的影響。對熱壓后和軋制后的SiC顆粒的形狀與分布、彌散粒子形貌、致密度與硬度進行研究，并分析與總結(jié)致密化過程中孔隙與沉積顆粒的變形。結(jié)果表明：在熱壓溫度480 ℃、壓力125 MPa，且當坯料直徑略小于熱壓模內(nèi)徑時進行熱壓會產(chǎn)生一定程度的剪切變形，有利于SiC顆粒的均勻分布和孔洞的閉合；此時彌散粒子粒徑為50~80 nm，晶粒粒徑為600~900 nm，位錯少，相對密度達98.8%，但仍殘留孔隙。軋制過程中的大剪切變形促進了沉積顆粒的變形和顆粒之間冶金結(jié)合，有利于提高材料的致密度和力學性能。經(jīng)480 ℃多道次熱軋，沉積顆粒邊界消失，彌散粒子釘扎位錯，Al12(Fe,V)3Si約為100 nm、晶粒約為1 μm，無明顯Al13Fe4相析出，材料相對密度達99.5%。當軋制總壓下量低于20%時，SiC顆粒無序分布，孔隙減少，密度和硬度增加；當總壓下量為20%~40%時，由于SiC顆粒相對基體轉(zhuǎn)動和滑動產(chǎn)生孔隙引起密度和硬度下降。總壓下量超過40%時，SiC顆粒的長軸方向平行于軋制方向，SiC顆粒與基體之間的間隙逐漸彌合，密度和硬度升高。當總壓下量達到95%，相對密度達99.5%。
關(guān)鍵字: 噴射沉積；顆粒增強；鋁基復合材料；致密
（1. Jiangsu Marine Resources Development Research Institute, Lianyungang 222005, China;
2. College of Mechanical Engineering, Huaihai Institute of Technology, Lianyungang 222005, China;
3. College of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China）
Abstract:SiCp/Al-8.5Fe-1.3V-1.7Si composite prepared by spray deposition were densified by hot pressing, and then were rolled into sheets. Effects of hot pressing parameters and rolling parameters on microstructure and mechanical properties were investigated. Shape and distribution of SiC particles, shape of dispersoids, density and hardness of the composite as-hot pressed and as-rolled were studied separately. Evolution of pores and deposited particles during densification process were discussed and summarized. The results show that hot pressing temperature of 480 ℃ and 125 MPa, and smaller diameter of the billet than the inner diameter of the hot die are benefit for homogeneous distribution of SiC particles and void closing. Dispersoids of the composite as-pressed is 50-80 nm in diameter, and grain is 600~900 nm in diameter with few dislocation in the grains. Relative density of the composite as-pressed is up to 98.8% with residual pores remaining. Large plastic shear strain of multi-pass hot rolling contributes to deformation of deposited particles and metallurgical bonding between the particles, subsequently benefits to densification and mechanical properties of the composites. After multi-pass hot rolling at 480 ℃, boundaries among deposited particles disappear, and dislocations are pinned by dispersoids in the matrix with Al12(Fe,V)3Si dispersoids of about 100 nm, and grains are about 1 μm in diameter without Al13Fe4 forming. Relative density of the composite as-rolled is up to 99.5%. SiC particles distribute randomly, and density and hardness increase because of pore reducing and eliminating when cumulative reduction is below 20%. Then density and hardness decrease because of pores resulted from rotation and sliding between SiC particles and the matrix when cumulatie reduction is 20%-40%. Long axis of SiC particle becomes parallel to rolling direction, pores between SiC particles and the matrix disappear, and density and hardness increase when cumulative reduction is over 40%. Relative density of the composite is up to 99.5% with cumulative reduction of 95%.
Key words: spray deposition; particle reinforcement; Al-matrix composite; densification
