新型W-Cu功能材料的制备及其性能研究

发布时间：2018-06-03 00:36

本文选题：W-Cu复合材料 + 功能梯度材料　；参考：《合肥工业大学》2016年硕士论文

【摘要】：W-Cu复合材料综合了W、Cu的性能,具有良好的导电导热性、较高的力学强度和耐腐蚀性能等,在电工电子、军工及能源领域得到了较为广泛的应用。现代高科技的发展,对W-Cu材料的组织性能提出了更高的要求,在某些应用场合下还需要具有特殊结构的W-Cu材料。因此近些年来,探索超细晶、全致密、高性能W-Cu材料及特殊结构W-Cu材料的制备,并开展其应用评价,成为W-Cu材料领域的研究热点。本文以获得具有梯度结构的W-Cu材料为重点,探索通过常规的粉末压制方法和轧膜成形方法制备该类材料,还考察了氧化物Sc2O3的添加对W-Cu材料组织性能的影响。论文为新型W-Cu功能材料的开发进行了初步的探索。论文首先以W粉和Cu粉为原料,通过机械混合获得不同组成的W-Cu混合粉(铜含量分别为15wt%,35wt%,55wt%),随后通过逐层铺粉,共压得到了W(Cu)含量呈层状分布的生坯,之后在H2气氛中烧结,获得了W-Cu复合材料烧结体。实验结果表明,上述层状生坯经1150℃烧结所得烧结体中,W(Cu)含量仍呈层状分布,且层与层之间界面结合良好。烧结体的相对密度可达95%以上,热导率达142W/(m·K),维氏硬度达到249-308HV,抗弯强度达到514-669MPa。本文为了获得大面积的W-Cu梯度材料,以W粉和Cu粉为原料,聚乙烯醇缩丁醛(PVB)为粘结剂,通过有机基轧膜工艺制备出了三种不同组成(铜含量分别为25wt%,50wt%,75wt%)的W-Cu生坯,再通过叠层共轧,得到了W(Cu)含量呈层状分布的复合生坯,之后在H2气氛中烧结,最终获得了W-Cu复合材料烧结体。实验结果表明,通过单层轧制,叠层共轧共烧,可以制备出形状尺寸可控,组织性能良好的层状梯度W-Cu复合材料。轧膜过程中粘结剂的用量对W-Cu层状梯度材料的致密度和性能有着明显的影响。当粘结剂用量为6%时,轧膜坯有较好的成形性,且成形坯的孔隙率较低。所得多层复合生坯经1150℃烧结后相对密度达93%以上。热导率为148 W/(m·K),维氏硬度达到294-345HV,抗弯强度达到574.8-725.6MPa。为了改善W-Cu材料的组织和性能,以(NH4)6H2W12O40、Cu(NO3)2·3H2O和Sc203等为原料,采用凝胶-共还原法制备了不同量Sc2O3(0-0.7wt.%)掺杂的W-Cu复合粉体。所得粉体经模压成形,所得生坯在1250℃于H2气氛中烧结,得到Sc2O3/W-20Cu复合材料烧结体。所得烧结体的相对密度高于97%,晶粒尺寸小于1μm,显微组织中W-Cu分布均匀,材料的电导率达到37%(IACS%),硬度为265HV,抗弯强度达910MPa。结果表明,适量Sc203的添加对W-Cu材料的烧结性能和电导率影响不甚明显,但可增加W-Cu复合材料的力学性能。添加0.5%的Sc203可使材料的维氏硬度提高10%以上,而添加0.3%的SC203使W-Cu材料的抗弯强度提高7.70%。
[Abstract]:W-Cu composite has comprehensive properties of W, Cu, good conductive and thermal conductivity, high mechanical strength and corrosion resistance. It has been widely used in the field of electrical, electronics, military and energy. The development of modern high-tech has put forward higher requirements for the organization and performance of W-Cu materials, and it needs to be used in some applications. In recent years, the preparation of ultrafine crystals, full compact, high performance W-Cu materials and special structure W-Cu materials and their application evaluation have become a hot topic in the field of W-Cu materials. This paper focuses on obtaining the W-Cu materials with gradient structure, and explores through conventional powder pressing and film forming process. The effects of the addition of oxide Sc2O3 on the microstructure and properties of W-Cu materials were also investigated. The development of the new W-Cu functional materials was preliminarily explored in this paper. The paper first took W powder and Cu powder as raw materials to obtain W-Cu mixed powders of different components by mechanical mixing (copper content was 15wt%, 35wt%, 55wt%), and then passed through the process. The W (Cu) content is distributed in layer by layer, and then sintered in the atmosphere of H2, the sintered body of W-Cu composite is obtained. The experimental results show that the content of W (Cu) is still layered in the sintered body obtained by the 1150 C sintering, and the relative density of the layer and layer is good. The relative density of the sintered body can reach 95%. Above, the thermal conductivity reaches 142W/ (M. K), the hardness of Vivtorinox reaches 249-308HV and the bending strength reaches 514-669MPa.. In order to obtain a large area of W-Cu gradient material, three kinds of different components (copper content of 25wt%, 50wt%, 75wt%) are prepared with W powder and Cu powder as raw material and polyvinyl butyral (PVB) as binder. In U, the composite blank with layered distribution of W (Cu) content was obtained by stacking co rolling, then sintered in the atmosphere of H2, and finally obtained the W-Cu composite sintered body. The experimental results show that the layered gradient W-Cu composite with the shape size controllable and good microstructure and properties can be prepared by single layer rolling and co burning. The amount of the binder in the process has an obvious effect on the density and performance of the W-Cu layered gradient material. When the binder dosage is 6%, the rolled billet has a better formability and the porosity of the formed billet is low. The relative density of the composite billet is over 93% after sintering at 1150 C. The thermal conductivity is 148 W/ (M. K), and the hardness of Vivtorinox reaches 294-345. HV, the bending strength reached 574.8-725.6MPa. in order to improve the microstructure and properties of W-Cu materials, and (NH4) 6H2W12O40, Cu (NO3) 2. 3H2O and Sc203 as raw materials, the W-Cu composite powders of Sc2O3 (0-0.7wt.%) doped with different quantities were prepared by the gel co reduction method. The relative density of the sintered body of -20Cu composite is higher than 97%, the grain size is less than 1 mu m, the distribution of W-Cu in the microstructure is uniform, the electrical conductivity of the material is 37% (IACS%), the hardness is 265HV, and the bending strength of 910MPa. shows that the addition of appropriate Sc203 has little effect on the sintering property and electrical conductivity of W-Cu material, but it can increase W. The mechanical properties of -Cu composites. Adding 0.5% of Sc203 can increase the hardness of the material by more than 10%, and the addition of 0.3% SC203 makes the bending strength of the W-Cu material increase by 7.70%.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB34

【相似文献】