Enhanced assessment of technological factors for Ti-6Al-4V and Al-Cu-Mg strength properties

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 23 No. 4 2021 а b c d Fig. 1. Samples for testing (Fig. 1, a ) and with a stress concentrator in the form of a hole ( d = 1.5 mm), in the center of the working part (Fig. 1, b ). Samples had the following parameters: thickness ( h = 2.1 mm), width ( b = 9 mm), concentration factor α σ = 6.49. Specimens from alloy D16 were also divided into two series: smooth (Fig. 1, c) and with a stress concentrator in the form of a weld (Fig. 1, d). Samples had the following parameters: thickness ( h = 1.5 mm), width ( b = 12 mm). The weld was formed using a laser. The width of the weld is equal to the thickness of the specimen. The strength of the weld was 0.85 of the strength of the base material. The studies make it possible to assess the in fl uence of design factors (stress concentrators) on the change in the characteristics of the state of the material under cyclic loading (as a result, on the resistance of the material to fatigue failure). Strain measurements were taken on a 25 mm base using an extensometer. The stress-strain diagram for VT6 and D16 samples is shown in Fig. 2. Mechanical properties of VT6 : – ultimate tensile strength σ u = 1045 MPa ( △ ), – yield stress σ 0.2 = 881 MPa ( ▲ ), – modulus of elasticity E = 102.600 MPa. Fig. 2. Tensile stress diagrams for VT6 and D16 samples