All articles. Vestnik MGTU

Effect of pulse frequency in laser shock peening on roughness and residual stresses of nickel alloy specimens

Fri, 29 May 2026 00:00:00 +0400

The effect of pulse frequency during laser shock peening on microhardness, roughness, crushing and residual stresses of the surface layer of flat nickel alloy samples is considered. Laser shock peening was performed by a low-power Nd:YAG laser with a pulse duration of 10 ns on one side of the sample. Acrylic paint was used as a protective layer. It was found that laser shock peening at a low frequency led to large compressive residual stresses of –0.44…–0.28 rel. units compared to other laser pulse frequencies. At a frequency of 3 Hz, laser impact treatment leads to a minimum compression depth (reduction in sample thickness) of 7.62 μm. Roughness after laser shock peening in all processing modes from 0.32 μm to 0.90 ... 1.50 μm. Microhardness increased by 1.2 ... 2.0 times. It is recommended to include an allowance for laser shock peening of 7...10 µm.
EDN: LIQYDT, https://elibrary/liqydt

Comparison of mechanical and corrosion characteristics of alumin alloy D16 after different types of age hardening

Mon, 01 Jun 2026 00:00:00 +0400

This paper examines the mechanical and corrosion properties of D16 aluminum alloy after natural and artificial age hardening to maximum strength. The yield strength for these heat treatments differs only slightly. Rockwell hardness measurements revealed that natural age hardening is most intense during the first 30 minutes, after which it subsides, but continues for up to 8220 minutes. Accelerated fatigue testing using the Lokati method was conducted on non-standard specimens with a lower theoretical stress concentration factor. The loading type was tension-compression. Tests were conducted in air at room temperature with a cycle asymmetry of R = -1. Fatigue testing allowed us to determine fatigue limits, which differ to a greater extent than other mechanical properties. Corrosion testing in an environment supersaturated with chloride ions revealed significant differences in the depth and number of pits for specimens subjected to different age hardening processes.
EDN: GMXHZJ, https://elibrary/gmxhzj

The use of hybrid polymer composite materials to regulate the temperature coefficient of linear expansion of forming equipment

Tue, 02 Jun 2026 00:00:00 +0400

The greatest effect from the use of polymer composite materials is achieved in structures that have the highest possible requirements for a combination of strength properties, dimensional accuracy and low weight. The main method of manufacturing such parts is autoclave molding, which combines pressure and high temperatures. The requirements for the accuracy and quality of polymer composite materials parts are growing, as a result of which more and more attention should be paid to the appropriate shaping equipment. The ideal equipment should ensure form stability under cyclic temperature loads of autoclave molding, as well as have the necessary set of mechanical characteristics. At the same time, the correspondence of the temperature coefficient of linear expansion of the tooling material and the molded part must be observed, since it is the condition of the tooling at the time of molding the product that determines its final shape. It is proposed to use hybrid polymer composite materials, combining glass, aramid, and carbon fibers as reinforcing fillers, as a material for manufacturing forming equipment capable of providing thermophysical parameters set by the material of the molded part.
EDN: JOUVXM, https://elibrary/jouvxm