PSI - Issue 65

E.G. Zemtsova et al. / Procedia Structural Integrity 65 (2024) 317–323 E.G. Zemtsova et al. / Structural Integrity Procedia 00 (2024) 000–000

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At the next stage of the work, samples of a volumetric composite material based on Al containing 1% and 5% of the reinforcing phase were manufactured and studied. Figure 3 shows a micrograph of the surface of a composite made of Al with the addition of 5% reinforcing phase by injection molding. For a detailed study of the surface of the samples, the elemental composition of the samples at several points of the surface was studied simultaneously with microscopy. It can be seen from the microphotographs that the composition of the samples corresponds to the declared one. Samples reinforced with a disproportionate phase of titanium carbide contain oxygen in addition to Al and Ti. The presence of oxygen may indicate an oxide film that is present on the surface of Al.

Fig. 3. Micrograph of the chipping of a composite Al sample with a 5% by weight reinforcing dispersed phase Al/nano TiC (Al@TiC).

In the production of bulk materials, the use of high temperature promotes the chemical reaction between carbide particles and the metal matrix, which contributes to the production of aluminum carbide, which embrittles the system and reduces the strength characteristics of the samples and significantly reduces the plasticity of aluminum composites. Studies of samples using X-ray phase analysis of an Al matrix composite showed the absence of an Al carbide phase. A composite Al matrix material reinforced with TiC carbide nanostructures with a size of less than 4 nm was obtained without forming an additional phase at the metal-ceramic interface of a metal matrix composite material (absence of an aluminum carbide phase). This made it possible to avoid embrittlement of the composite. In the course of the work, composites with an Al matrix containing 1% and 5% of the reinforcing phase (Al@TiC) were obtained by injection molding. A comparison sample was also obtained, a composite with an aluminum matrix containing 5% of the reinforcing phase of microbial TiC with a particle size of 20 microns. To identify their mechanical properties, mechanical tests were carried out. The revealed characteristics are presented in Table 1. The mechanisms of hardening of an Al-based composite are revealed. All composite aluminum matrix samples obtained by injection molding show increased strength properties when tested for uniaxial tension. 3.2. Mechanical uniaxial stretching tests

Table 1. Mechanical characteristics of composites based on an aluminum matrix.

Sample No.

Reinforcing phase

Reinforcing phase content, mass. %

Ultimate strength σ, MPa at 200C

Strength gain σ, MPa

Ɛ, %

1 2 3 4

No

-

50 58 81

-

35

TiC, 20 micron Al/ nano TiC Al/ nano TiC

5 1 5

+15 % +52% +82%

8

32 30

90.5