the designed composites with 20 vol.% fiber fraction can be completely realized using the selected materials and the prepared preforms cannot have pores. As regards the slurry properties, they are directly concerning with the relative ratio of the three parts (PMMA, acetone and powders) composing the slurry.The slurry viscosity is mainly determined by the acetone, while the preform strength completely relies on the content of PMMA binder. A slurry with high viscosity is difficult to completely penetrate into the space between fibers, and thus the prepared preforms have macro-pores, as shown in Fig. 1a; whereas, a slurry with low viscosity is difficult to be coated on the fibers to reach a required thickness, and the powders in the slurry tend to precipitate because of the long solidifying time, as illustrated in Fig. 1b.
Besides, preform with more PMMA has higher strength. Low content of PMMA may result in fiber peeling off, as shown in Fig. 1c.However, high PMMA content can decrease the electric conductivity of the preform, which does not benefit the subsequent wire cutting.The optimum slurry was finally determined, which has a composition of 10 g PMMA, 70 ml acetone and 60 g Ti and Al powder mixture. A preform produced with the optimum slurry is shown in Fig. 1d and its elemental distribution of Ti, Al, C is shown in Fig. 2. It can be seen that the preform, without macro-pores,exhibits a uniform fiber distribution and homogeneous dispersion of the Ti and Al powders. Finally, qualified preforms with a fiber
fraction of about 10 vol.% were successfully prepared.
the designed composites with 20 vol.% fiber fraction can be completely realized using the selected materials and the prepared preforms cannot have pores. As regards the slurry properties, they are directly concerning with the relative ratio of the three parts (PMMA, acetone and powders) composing the slurry.The slurry viscosity is mainly determined by the acetone, while the preform strength completely relies on the content of PMMA binder. A slurry with high viscosity is difficult to completely penetrate into the space between fibers, and thus the prepared preforms have macro-pores, as shown in Fig. 1a; whereas, a slurry with low viscosity is difficult to be coated on the fibers to reach a required thickness, and the powders in the slurry tend to precipitate because of the long solidifying time, as illustrated in Fig. 1b. Besides, preform with more PMMA has higher strength. Low content of PMMA may result in fiber peeling off, as shown in Fig. 1c.However, high PMMA content can decrease the electric conductivity of the preform, which does not benefit the subsequent wire cutting.The optimum slurry was finally determined, which has a composition of 10 g PMMA, 70 ml acetone and 60 g Ti and Al powder mixture. A preform produced with the optimum slurry is shown in Fig. 1d and its elemental distribution of Ti, Al, C is shown in Fig. 2. It can be seen that the preform, without macro-pores,exhibits a uniform fiber distribution and homogeneous dispersion of the Ti and Al powders. Finally, qualified preforms with a fiberfraction of about 10 vol.% were successfully prepared.
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