Multi-criteria optimization by the «ideal point» method of raw material composition for composite blank manufacturing

Abstract

The paper provides the results of an experimental study into the properties of compressed and sintered compacts of the following powders: VT-22 high-strength titanium alloy manufactured by plasma spraying of industrial titanium production waste, PTM-1 grade titanium manufactured by the hydrate-calcium method, and PV-N70Yu30 nickel-aluminum alloy. It was shown that charge composition selection for composite blank manufacturing is connected with the need to ensure optimization of several competing target functions. The relative density and strength of compacts under axial compression after sintering, as well as charge cost were chosen as optimization criteria. The problem was set and the method was proposed to select an optimal charge composition providing the necessary values of density, strength, as well as relatively low cost of products. The problem of multi-criteria optimization was solved based on the ≪ideal point≫ method. The results of calculations were compared with the previously obtained solutions of the problem under consideration using the Pareto method, linear programming, and generalized criterion. It was shown that different methods of multi-criteria optimization lead to significantly different results. In this case, the ≪ideal point≫ method gives the minimum discrepancy between the experimental and model values of the optimization criteria selected. The results of this study were used to create an expert system for the multi-criteria optimization of composite manufacturing processes. The charge composition obtained by the «ideal point» method was transferred to an industrial plant where an axially symmetric part was manufactured. The ultimate strength and relative density of the manufactured part material were in conformity with the predicted values.

Cluster model of the porosity of spongy titanium briquettes at the stage of pressing

“…This approach will enable avoiding a critical error in the presentation of the distribution of loading on a particle in modeling the structure formation of powder composites [8][9][10][11] when the number of contact points does not correspond to the actual one. Though the model of space filling by Kelvin [24], applied by researchers [13] while modeling the load on a given particle, is reasonable, the cluster cuboctahedral model makes it possible to describe the actual processes more accurately.…”

“…Paper [8] presented the multi-criteria approach using the perfect point method. The approach was based on earlier research by authors of [9], related to modeling the plastic flow of spongy titanium within one particle using the Drucker-Prager curve, which was approximated through Bernoulli lemniscate.…”

Multi-Criteria Selection of Quantitative Composition of Alloying Elements of Maraging Steels of the Fe–Cr–Ni–Mo System with an Improved Set of Mechanical Properties

“…Analysis of publications [8][9][10][11][12][13] for finding the steel and alloy quantitative chemical composition and its effect on strength properties has demonstrated use in plan of the accuracy of using regression models in order to predict material properties [14]. In addition, optimized methods used in [15] ("ideal point" method) have made it possible not only to predict, but also to reveal, the optimum quantitative composition of chemical elements included from the point of view of the best (greatest) values of test material mechanical properties.…”