## 3 Results and Discussion of the Research Results
It has also been shown that boron introduced in the form of an aluminum master alloy dissolves slowly and tends to agglomerate, which may reduce the effectiveness of the modification. However, it is believed that boron completely dissolves in the master alloy with silicon [68]. These views may explain the reason why the master alloy containing silicon has a more effective effect than that based only on aluminum. These views are also confirmed by the results of research on the microstructure and mechanical properties of hypoeutectic silumin [29; 55]. In the second series of tests, it was decided to check the influence of the AlSi7 master alloy with 0.06% Ti and 0.06% B added in the proportions 1:1, 2:1, 3:1, 4:1 and 5:1 (TiB, Ti2B, Ti3B, Ti4B and Ti5B, respectively) on the mechanical properties of the AlSi7 Mg alloy (Figure 7). Figure 6: XRD of AlSi7 Mg alloy with (0.06% Ti + 0.06% B + 7% Si + Al). After modifying the AlSi7 Mg alloy with the master alloy (TiB + AlSi7), values of Rm = 166 MPa (Figure 7a), A = 3.3% (Figure 7b) and H = 59 HB (Figure 7c) were obtained, which represents an increase in strength by 21% in compared to the unmodified alloy, as well as an increase of 312% in elongation and 10% in hardness. After increasing the titanium content to 0.12%, the strength increased to 170 MPa, the elongation to 4.5% and the hardness to 61 HB. After modifying the master alloy (Ti3B + AlSi7), strength (Rm) = 175 MPa, elongation (A) = 5.5% and hardness (H) = 63 HB were obtained. These are the highest values for this phase of research. After increasing the share of titanium in the master alloy to the Ti4B proportion, a slight decrease in mechanical properties was noted to Rm = 172 MPa, A = 4.2% and H = 62 HB. After modifying the silumin with the master alloy (Ti5B + AlSi7), another reduction in mechanical properties was noted (Rm = 169 MPa, A = 4.9% and H = 61 HB). There are works available in which the authors suggest the possibility of boron removal with excessive Ti addition resulting from the formation of TiB2 particles [68]. This could explain the decrease in the mechanical properties of the tested silumin with an increasing share of titanium. In the second phase of the second series of tests, it was decided to check the influence of the AlSi7 master alloy with 0.06% Ti and 0.06% B added in the proportions 1:1, 1:2, 1:3, 1:4 and 1:5 (TiB, TiB2, TiB3, TiB4 and TiB5, respectively) on the mechanical properties of the AlSi7 Mg alloy (Figure 8). Figure 7: Mechanical properties the AlSi7 Mg alloy without modification and after modification with AlSi7 + (Ti\({}_{x}\)B) master alloy for Ti from 0.06% to 0.3% and B = 0.06%: (**a**) tensile strength, (**b**) elongations, (**c**) Brinell hardness. After the modification of the AlSi7 Mg alloy with the master alloy (TiB2 + AlSi7), an increase in mechanical properties was found, both in comparison to the unmodified alloy and in comparison to the modification of the master alloy (TiB + AlSi7). The tensile strength was Rm = 167 MPa (Figure 8a), elongation (A) = 4.3% (Figure 8b) and hardness (H) = 60 HB (Figure 8c). An increase in some parameters was observed compared to the master alloy (TiB + AlSi7). There was a significant increase in elongation, which amounted to 30%, while the strength and hardness oscillated within the measurement error. The observed increase in parameters compared to the mortar (TiB + AlSi7), i.e., strength and hardness, were within the measurement error, while the increase in elongation is significant and amounts to 30%. After further increasing the amount of boron in the modifier by introducing the components TiB3, TiB4 and TiB5 into the master alloy, a gradual decrease in mechanical properties was achieved. Their reduction was due to the increase in the amount of boron in relation to titanium. A reduction in strength from 162 MPa for TiB3 to 158 for TiB5 (Figure 8a), elongation from 3.3 to 3.2% (Figure 8b) and hardness from 58 to 57 HB (Figure 8c) were obtained. The reduction in all three of the above mechanical parameters is not significant.