Principles of Creep-Resistant Aluminum Alloys Development

Abstract

The work is devoted to monitoring and studying the principles of obtaining creep-resistant Al-based alloys. It is shown that aluminum alloys are constantly expanding their application fields. At the same time, the requirements for a number of aluminum alloys are also growing, which determines their wider use in extreme conditions and, in particular, at elevated temperatures. Examples of parts and details, made of such materials, are used in car engines and special equipment, turbine impellers, parts of heat exchangers and collectors, fittings, cladding elements, and casing parts for aviation and space purposes, etc. Development and production of new creep-resistant materials on the basis of aluminum with the increased level of operational characteristics demands detailed studying of mechanisms and ways maintenance of their optimum structural-phase conditions and finding of effective ways to produce them. The presented work considers the existing methods and principles of efficient creep-resistant aluminum alloys production, among which the greatest attention is paid to the principles of production of cast alloys, as the most profitable in terms of mass production and economic efficiency. It was shown that the main principles of achieving this goal include: the use of alloying elements (Cr, Mn, Fe, Co, Ni, Cu) and modifiers (Ti, Zr, Mo, Hf), which will promote the formation of stable insoluble phases with low diffusion activity and noticeable cubic or close to cubic morphology in a metal matrix of the alloy; Creation of eutectic alloys, including silicon-free compositions, which would consist a large proportion of high-temperature phases with favorable morphology; The temperature of the eutectic transformation should be as high as possible; Introduction of technological principles of melts casting and preparation, that are able to effectively grind the structure of the alloy and increase the solubility of insoluble components by creating specific thermodynamic conditions.

Recent Progress in Creep-Resistant Aluminum Alloys for Diesel Engine Applications: A Review

“…Aluminum-based matrix composites (AMCs) combine an Al matrix with reinforcing phases (borides, carbides, oxides, nitrides, and their combinations) in the form of particles, whiskers, or fibers, leading to the development of lightweight and heat-resistant diesel engine components [37][38][39]. Some recent studies on this subject are presented below.…”

“…Al-Cu alloys [33][34][35][36], metal-matrix composites [37][38][39][40][41][42][43][44][45], and additively manufactured aluminum [46][47][48][49][50][51][52] can be used as selective reinforcement materials. Nano-structured aluminum [60][61][62][63][64][65][66][67][68][69] can be used as inserts to improve the creep resistance of the aluminum diesel engine in the inter-valve zone if the thermal stability can be improved.…”