Improving product performance by forming surface compositions from shape memory effect materials with a gradient of properties and phase transformation temperatures

Abstract

We have developed a flow chart for structure and architecture of multilayer surface composition made of multicomponent materials with shape memory effect (SME materials) for different purposes. These compositions have different temperatures of phase transformations. Complex technology of surface composition was carried out in a proprietary installation in conditions of complex high-energy effects. These effects included mechanical activation of deposited powder material, high-velocity oxygen fuel spraying with the subsequent thermal, and thermomechanical treatment in a single vacuum cycle with the ability to supply powder to different zones of the gas flow. The deposition sequence of functional layers, their composition, thickness, structurephase state, and dispersity are determined by operating conditions and control of the processing mode. For example, surface composition, "Steel-Ni-TiNiZr-TiNiCo," shows that the use of SME materials allows to create a surface composition, which is functionally oriented not only to improve the performance properties, such as wear strength and corrosion resistance, but also to improve durability and vitality because of the special properties of materials with shape memory composition and architecture. Experimental studies have demonstrated the effectiveness of technologies developed in improving the performance properties.

The effect of surface coating by shape memory alloys on mechanical properties of steel

“…In the subsequent technological cycle, stage-by-stage heat treatment was carried out. 7 Temperature T and reversible deformation of phase transformations in the coatings were the following: for TiNi T = 292-374 K, ε r = 2.5-2.9%; for TiNiCo T = 189-331 K, ε r = 2.1-2.3%; for TiNiZr T = 459-571 K; ε r = 2.1-2.3%. The thickness of SMA coatings was varied in the range 0.5-1.0 mm.…”

“…After coating, the specimens were annealed in argon at T = 1,073 K for 0.5-1.0 h. In addition, thermomechanical treatment by ultrasonic action was also used. 7 In order to assess the quality of the functional layers of the composition "coating-base metal," surfacemodified specimens were tested for the following characteristics: fatigue strength; adhesion; wear with the ability to register temperature during testing; and microhardness. Rotating bending fatigue tests was carried out using smooth specimens to estimate fatigue resistance curves.…”

“…Such estimates of the efficiency of coatings are given in the details. 7 For example, it was shown that the durability of propellers of sea-going ships can be increased by SMA coatings by 5 Ä 10 times or more.…”

“…4,5 Their feature is not only a change in the local and integral mechanical properties achieved in traditional methods but also the property of adaptability of the SMA to thermomechanical and corrosion-cavitation operational influence. 6,7 The present paper deals with microstructure and mechanical properties of the steel with composite SMA coatings.…”

Influence of Mechanical Activation and Mechanical Alloying on the Structure, Phase State of the Fe-Ni-Co-Al-Nb Powder Composition and on High-Entropy Coatings Based on it

“…Among the huge variety of high-entropy alloys, poorly studied HEAs with thermoelastic phase transformations, including those with shape memory effect (SME), occupy a special place [4,5]. The peculiarity of these alloys is their ability to exhibit structural adaptive properties during operation under certain conditions [6][7][8]. The use of high-entropy SME alloys in surface compositions significantly expands the possibilities of surface modification in increasing the durability and survivability of products.…”