This paper is devoted to the possibility of increasing the mechanical properties (tensile strength, yield strength, elongation and hardness) of high pressure die casting (HPDC) hypoeutectic Al-Si alloys by high melting point elements: chromium, molybdenum, vanadium and tungsten. EN AC-46000 alloy was used as a base alloy. The paper presents the effect of Cr, Mo, V and W on the crystallization process and the microstructure of HPDC aluminum alloy as well as an alloy from the shell mold. Thermal and derivative analysis was used to study the crystallization process. The possibility of increasing the mechanical properties of HPDC hypoeutectic alloy by addition of high-melting point elements has been demonstrated.

The paper presents the results of microstructure tests of EN AC-46000 hypoeutectic Al–Si alloy with and without high-melting-point elements: chromium, molybdenum, vanadium, and tungsten. The above-mentioned elements were used individually or simultaneously in various combinations. The tested castings were made using two technologies: shell molding and high pressure die casting (HPDC). Using X-ray diffraction and microanalysis of the chemical composition an attempt to determine the phase structure of the tested alloy was made. It has been shown that the microstructure of the base alloy consists of dendrites of α(Al) solid solution and complex eutectic mixtures: ternary α(Al) + Al₁₅(Fe,Mn)₃Si₂ + β(Si) and quaternary α(Al) + Al₂Cu + AlSiCuFeMgMnNi + β(Si). High-melting point elements, regardless of the combination used, attach mainly to intermetallic phases rich in Fe and form the Al₁₅(Fe,Mn,M)₃Si₂ phase, where M is any high melting point element or a combination of such elements. It has been shown that the area fraction of the above-mentioned phase increases with increasing content of high melting point elements. A greater area fraction of the Al₁₅(Fe,Mn,M)₃Si₂ phase in the casting from the shell mold in relation to the high pressure die casting has been also found.

Composite materials based on Al and Al4Cu with the addition of SiC particles (2.5; 5; 7.5; 10 wt.%) were produced in low-cost conventional powder metallurgy processes involving mixing, compacting with a pressure of 300 MPa, and sintering at 600 °C in a vacuum atmosphere. An attempt was made to create a relationship between the vacuum sintering and the microstructure and mechanical properties of Al/SiC composites. The strength of the matrix-reinforcing interface depends on the chemical composition of the components; therefore, the influence of 4 wt.% copper in the aluminum matrix was investigated. Comprehensive microstructural and mechanical properties (including Brinell hardness, compressive and flexural strength measurements) of the produced composites were measured. The addition of 2.5 wt.% SiC to the Al4Cu matrix improved the mechanical properties of the composites compared to the matrix. In the composite with the addition of 2.5 wt.% of SiC, while the addition of the reinforcement did not affect the hardness and compressive strength and caused a rapid decrease in the flexural strength compared to the aluminum matrix, the addition of Cu to the matrix of this composite improved hardness (from 25 to 49 HB), compressive strength (from 423 to 618 MPa), and flexural strength (from 52 to 355 MPa).

Quaternary powder mixtures yNi–20Cr–1.5Al–xTiC_p (y = 78.5, 73.5, 68.5; x = 0, 5, 10) were deposited on ferritic 10CrMo9–10 steel to form on plates ex-situ composite coatings with austenitic-based matrix. Plasma deposition was carried out with various parameters to obtain eight variants. The microstructure, chemical composition, phase constitution, phase transformation temperatures, and microhardness of the two reference TiC_p-free coatings and six ex-situ composites were investigated by X-ray diffraction, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermodynamic simulation, and Vickers microhardness measurements. All composites had an austenite matrix with lattice parameter a = 3.5891–3.6062 Å, calculated according to the Nelson–Riley extrapolation. Microstructural observations revealed irregular distribution of TiC_p in the composites. Large particles generally occurred near the external surface due to the acting buoyancy effect, whereas in the interior smaller particles, with an equivalent radius around 0.2–0.6 μm, were present. Due to initial differences in the chemical composition of powder mixtures and also subsequent intensive mixing with the low-alloy steel in the liquid pool, the matrix of the composites was characterized by various chemical compositions with a dominating iron concentration. Interaction of TiC_p with matrix during deposition led to the formation of nano-precipitates of M₂₃C₆ carbides at the interfaces. Based on the ThermoCalc simulation, the highest solidus and liquidus temperatures of the matrix were calculated to be for the composite fabricated by deposition of 73.5Ni–20Cr–1.5Al–5TiC_p powder mixture at I = 130 A. The mean microhardness of the TiC_p-free coatings was in the range 138–146 μHV0.1, whereas composites had hardnesses at least 50% higher, depending on the initial content of TiC_p.

In this work, two kinds of silicon nitride-based composites, namely, those with titanium nitride or silicon carbide additives, were sintered using the hot pressing technique (HP). The phase composition, microstructure, and mechanical and elastic properties of the materials were characterized. Three-dimensional geometric models of the composites were created on the basis of microstructure parameters. Using these models, bulk residual thermal stresses were calculated by the finite element method (FEM). Surface stresses were determined using the XRD method of sin²ψ.

Grain-oriented electrical steel (GOES) has been used for many years for application in transformed cores due to its excellent magnetic properties. Magnetic properties are strongly influenced by obtaining a texture with a certain orientation (110) [001] for BCC structure. This is related to the easy direction of magnetization [001]. So far, the main research has been focused on obtaining a strong texture in the last stages of the process. The aim of the present study was to additionally trace textural changes for a slab after the continuous casting (CC) process and for a sheet after the hot rolling process. The scope of such an analysis has not been conducted before. With regard to the state after continuous casting (CC), the texture was related to measurements of the anisotropy of Barkhausen magnetic noises and the macrostructure of the slab. Based on the X-ray diffraction examinations that compared the texture intensity calculated from the texture coefficient of the slab, the hot rolled steel and the final product of grain-oriented electrical steel contained 3.1% of Si. The studies performed with the material taken from three different production steps showed high differences in the values of textural intensity indicating the occurrence of a crystallization texture, especially in the area of the columnar crystal zone; textural weakness after the hot rolling process and high texturing in the final product for textural components corresponding to the desired Goss texture.