摘要
采用热压后多道次热轧制备喷射沉积SiC_p/Al-8.5Fe-1.3V-1.7Si复合材料板材,研究热压、轧制工艺参数对复合材料显微组织、力学性能的影响。对热压后和轧制后的SiC颗粒的形状与分布、弥散粒子形貌、致密度与硬度进行研究,并分析与总结致密化过程中孔隙与沉积颗粒的变形。结果表明:在热压温度480℃、压力125 MPa,且当坯料直径略小于热压模内径时进行热压会产生一定程度的剪切变形,有利于SiC颗粒的均匀分布和孔洞的闭合;此时弥散粒子粒径为50~80 nm,晶粒粒径为600~900 nm,位错少,相对密度达98.8%,但仍残留孔隙。轧制过程中的大剪切变形促进了沉积颗粒的变形和颗粒之间冶金结合,有利于提高材料的致密度和力学性能。经480℃多道次热轧,沉积颗粒边界消失,弥散粒子钉扎位错,Al_(12)(Fe,V)_3Si约为100 nm、晶粒约为1μm,无明显Al_(13)Fe_4相析出,材料相对密度达99.5%。当轧制总压下量低于20%时,SiC颗粒无序分布,孔隙减少,密度和硬度增加;当总压下量为20%~40%时,由于SiC颗粒相对基体转动和滑动产生孔隙引起密度和硬度下降。总压下量超过40%时,SiC颗粒的长轴方向平行于轧制方向,SiC颗粒与基体之间的间隙逐渐弥合,密度和硬度升高。当总压下量达到95%,相对密度达99.5%。
SiCp/A1-8.5Fe-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 ~C 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 ~C, boundaries among deposited particles disappear, and dislocations are pinned by dispersoids in the matrix with All2（Fe,V）3 Si dispersoids of about 100 nm, and grains are about 1 ~tm in diameter without All3Fe4 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 compos
作者
贺毅强
李俊杰
周海生
冯立超
陈志钢
HE Yi-qiang LI Jun-jie ZHOU Hai-sheng FENG Li-chao CHEN Zhi-gang(Jiangsu Marine Resources Development Research Institute, Lianyungang 222005, China College of Mechanical Engineering, Huaihai Institute of Technology, Lianytmgang 222005, China College of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2017年第7期1352-1360,共9页
The Chinese Journal of Nonferrous Metals
基金
江苏省自然科学基金资助项目(BK20141250
BE2015100)
江苏省高校自然科学研究面上项目(14KJB430005)
国家自然科学基金资助项目(51004050
51301044)
连云港市科技计划资助项目(CG141
CXY1404)
江苏省海洋资源开发研究院开放基金资助项目(JSIMR201222)
江苏高校品牌专业建设工程资助项目(PPZY2015C214)~~
关键词
喷射沉积
颗粒增强
铝基复合材料
致密
spray deposition
particle reinforcement
Al-rnatrix composite
densification
