Preparation of Porous Diamond Preforms for Infiltrating Aluminium Alloy

[摘要] Diamond/Al composites with high volume fraction of diamond particles possess high hardness and so they are difficult to be machined subsequently. The near-net-shape preparation of diamond/Al composites can be successfully realized by combined process of diamond preforms by powder injection molding and then aluminium alloy infiltrating the preforms. The process of diamond preforms prepared by powder injection molding was studied, which involved the choice of the binder, the injection molding process and the sintering process. In the experiment, Cu was coating on diamond powder and then sintering diamond preforms with Cu-coated to obtain the strength for the handling operation. Research results showed that, the feedstocks had excellent rheological properties and higher solid volume fraction could be obtained, when the binder composed of 60% paraffin, 30% high density polyethylene and 10% stearic acid as the carrier was used in the powder injection molding. In powder injection molding, the best injection temperature was 160∼170°C and the best injection pressure was 70∼80MPa. When the diamond preforms were sintering at 950°C for 35min, its strength could reach 8MPa and open porosity was close to 100%.

[发布机构] Beijing National Innovation Institute of Lightweight Co. Ltd., Beijing; 100083, China^1;Henan Engineering Research Center for Wear of Materials, Zhengzhou; 471000, China^2;Institute for Advanced Materials and Technology, University of Science and Technology, Beijing; 100083, China^3

[效力级别] 无线电电子学 [学科分类] 材料科学（综合）

[关键词] Diamond particles;High volume fraction;Injection molding process;Injection pressures;Injection temperature;Powder injection molding;Rheological property;Solid volume fraction