Types Of Alloys Research Articles

Nanoalloys Composed of Platinum Group Metals and p‐Block Elements for Innovative Catalysis

Alloy nanoparticles based on platinum group metals (PGMs) have been intensively investigated in various fields, especially in catalysis. Recently, the scope of alloying has expanded to include not only d‐block transition metals but also p‐block elements, which have a wide range of properties that are very different from those of d‐block transition metals. By alloying PGMs with p‐block elements, the electronic structure and surface properties of the catalysts can be tuned, enhancing their catalytic performance. The focus of this review is on PGM–p‐block element nanoalloys, their synthesis methods, characterization techniques, and catalytic properties. In addition to typical binary crystalline alloys, such as solid‐solution and intermetallic alloys, this review also highlights the potential of multielement, amorphous, or liquid alloys, which have recently garnered much attention. The review aims to provide valuable perspectives for the development of PGM‐based sustainable and innovative catalysis, while also addressing the current challenges and future directions in this field.

Analysis of relative uncertainty in impact experiment for three typical aluminum alloy materials

Analysis of relative uncertainty in impact experiment for three typical aluminum alloy materials

Peritectic solidification mechanism of substantially undercooled liquid Fe-Y-B ternary alloys

Liquid Fe84Y10B6 and Fe74Y16B10 peritectic type alloys were substantially undercooled up to 382 (0.25 TL) and 400K (0.26 TL) with drop tube technique. The molecular dynamics simulation results revealed that the former alloy was characterized by larger Fe, Y and B self-diffusion coefficients and activation energies. In low undercooling regime, γFe phase in Fe84Y10B6 alloy and Y2Fe17Bx phase in Fe74Y16B10 alloy formed preferentially, faceted τ1(Y2Fe14B) phase subsequently developed through peritectic transition. With the increase of undercooling, peritectic transition was promoted by the refined primary phases. Once liquid undercoolings reached certain critical values, a stronger nucleation driving force is provided for τ1 phase, resulting in its direct nucleation and growth by suppressing the formation of primary phases and the following peritectic transformations. If liquid undercooling rose further, there occurred the faceted to non-faceted growth mode transition of the main peritectic τ1 phase. This indicates that high undercooling and rapid solidification is an effective approach to modulate phase transition pathway and microstructural evolution of rare earth alloys.

Hydrogen storage in a novel BCC-structured TiCrW alloys

Body-centered cubic (BCC)-type alloys possess a high theoretical hydrogen storage capacity, yet their high cost, limited effective hydrogen storage capacity, and poor cyclic properties remain challenges. In this work, a novel and cost-effective (Ti0.44Cr0.56)94W6 BCC phase alloy was successful prepared by W doping and heat treatment. The alloy exhibits an effective hydrogen desorption capacity of 2.44 wt% with minimal 9 % degradation over 300 cycles. The microstructural analysis shows that W doping inhibits the formation of Ti-rich phase and Laves phase in the alloy, and makes the alloy form a single BCC phase structure with higher hydrogen storage sites. After heat treatment, the alloy exhibits remarkable hydrogen de-/absorption kinetics and superior plateau characteristics, which reduces the plateau slope factor from 5.32 to 0.18, and increases the effective hydrogen desorption capacity from 1.09 to 2.44 wt%. This alloy’s activation energy and enthalpy change in dehydrogenation process are determined to be 11.64 and 44.31 kJ/mol, respectively. First-principles simulations further illuminated that the incorporation of W doping diminished the migration energy barrier of hydrogen and compromised the structural stability of the hydride. Furthermore, the structural evolution during de-/hydrogenation was analyzed, elucidating the mechanism of the alloy’s cyclic performance decay. These findings offer theoretical insights that guide the development of novel solid state hydrogen storage materials.

Investigation of the Effect of Cutting-Edge Rounding on Surface Quality in Milling of Al 7075 and Al 6082 Alloys

Al 7075 and Al 6082 alloys are alloys that are widely used in many sectors, especially aviation and automotive. During their processing along with the widespread use of those alloys, significant machinability problems such as low surface quality due to chip accumulation (Built Up Edge-BUE) on the cutting edge are observed. In this study, the effect of cutting-edge corner rounding and machining parameters on surface roughness in milling of Al 7075 and Al 6082 alloys were experimentally investigated. To determine the effect of cutting-edge rounding, two different corner rounding values (5.5-6 µm and 7-9 µm) were applied and compared with standard/coated and standard/uncoated tools in terms of machining performance. In the experimental studies, cutting parameters were determined as two different cutting speeds (300 m/min, 400 m/min) and two different feed rates (0.085 mm/tooth, 0.11 mm/tooth). With each tool, peripheral milling was performed on four sides of the prismatic test specimens under dry machining conditions. Taguchi L8 orthogonal array experimental design was used as the experimental design. Analysis of variance (ANOVA) was performed to evaluate the effects of cutting parameters on surface roughness and the reliability of all results was above 85%. The results of the analysis of variance revealed that the alloy type was more effective on the surface roughness. In the surface roughness measurements, the best surface roughness values (Ra=0.14 µm) were obtained in the experiments performed with a standard/coated cutting tool using a cutting speed of 300 m/min and a feed rate of 0.11 mm/tooth.

The Influence of the Strain Rate on Texture Formation During the Plane Strain Compression of AZ80 Magnesium Alloy.

Controlling microstructure and texture development is a key approach to improving the formability of magnesium alloys. In this study, the effects of the strain rate and initial texture on the texture evolution of magnesium alloys during high-temperature processing are investigated. The plane strain compression of three types of AZ80 magnesium alloys with different initial textures was assessed at 723 K and a train rate of 0.0005 s-1. Work softening was consistently observed in the stress-strain curves of all samples. However, the peak stress varied depending on the initial texture, with lower peak stress observed under conditions favoring prismatic slip. Under these conditions, the activation of non-basal slip suppressed the formation of basal texture. The texture shifted and developed parallel to the transverse direction when prismatic slip was dominant. In contrast, the activation of pyramidal slip led to the formation of a basal texture tilted by 25° from the (0001) plane. The effects of recrystallization and grain boundary migration on texture development were minimal. This study contributes to understanding the texture development mechanisms in magnesium alloys and provides insights into improving their workability and ductility through texture modification.

Technology of manufacturing copper and bronze tools of the Petrovka Culture of the Southern Trans-Urals and Middle Tobol region

The article presents the results of metallographic analysis of the Petrovka Culture tools from the southern Trans-Urals and Middle Tobol River region of the 19th–18th centuries BC (47 items). A certain correlation has been determined between the functional purpose of an item, the type of raw material, and the tool manufacturing scheme. The tools were mainly made of copper contaminated with impurities, obtained from oxide-carbonate ores with the addition of chalcocite-covellite minerals. A butted axe, sickles, knives with handles, tanged chisels, hooks, and some awls were made of copper, both by casting in a mold with subsequent finishing and by forming forging. Copper tools obtained by casting often had casting defects — shrinkage cracks and warping of the metal. In most cases, the tools were finished either in the regime of incomplete hot forging at 300–500°C, or hot forging at 600–800°C and pre-melting temperatures of 900–1000°C. During the Petrovka period, tin and tin-arsenic bronze started being used for manufacturing adzes, chisels, handled knives, the majority of awls, needles, spear-heads, and arrows. More progressive types of alloys in terms of fluidity, filling mold without defects in the form of low-alloy tin and tin-arsenic bronzes (Sn up to 7%, As up to 4%) came from related tribes of the Petrovka Culture of Saryarka, possibly from the Petropavlovsk Ishim region. The resulting castings were of high quality with smooth surface without metal warping defects. Subsequent finishing was carried out by selecting optimal heat treatment regimes mainly at 600–800°C or 900–1000°C, as well as using incomplete hot forging at 300–500°C. The hardness of the tools finished by forging with heating significantly exceeded the microhardness of the processed copper by 1.5–2 times.

Influence of Surface Roughness on the Adhesion of Hydroxyapatite Coatings to Titanium and Titanium Alloy Surfaces: A Systematic Review of in vitro Experimental Studies.

This systematic review gathered evidence to identify the influence of roughness on titanium surfaces on the adhesion of hydroxyapatite coatings. This research followed the PRISMA guidelines and was registered on the Open Science Framework (osf.io/cxrsf). In vitro studies were searched on Science Direct, PubMed, Embase, Scopus, Google Scholar and in the references of the articles included. Two independent reviewers selected the studies based on the inclusion and exclusion criteria. The risk of bias analysis was carried out using the adapted Joanna Briggs Institute quasi-experimental study tool. 2890 articles were found and after applying the selection criteria 22 were chosen to be read in full. 9 studies were excluded because they did not evaluate substrate roughness or coating adhesion. Finally, 13 studies composed this systematic review. Of these, 4 indicated that greater titanium roughness provides better adhesion of the hydroxyapatite coating, 7 that in addition to roughness, other factors play a role in this process, and 2 other studies presented divergent results. Surface roughness has influence on the adhesion of hydroxyapatite coatings to titanium. However, the type of titanium alloy, the thickness of the coating and other characteristics also affect the adhesion process and should be considered.

Experimental and Mathematical Modelling Investigation of Plasma Electrolytic Oxidation (PEO) for Surface Hardening of 20Ch Steel.

This study aimed to develop an alternative surface hardening technique for low-carbon steel alloy type 20Ch using plasma electrolytic oxidation (PEO). The surface hardening of 20Ch alloy steel samples was achieved through PEO in a Na2CO3 electrolyte solution. Optimal processing parameters were determined experimentally by measuring voltage and applied current. Quenching was performed in the electrolyte stream, and plasma was ionised through excitation. A mathematical model based on thermal conductivity equations and regression analysis was developed to relate the key parameters of the hardening process. The results from both the experimental and mathematical models demonstrated that PEO significantly reduces hardening time compared to traditional methods. The microstructural images revealed the transformation of the coarse-grained pearlite-ferrite structure into quenched martensite. Vickers microhardness tests indicated a substantial increase in surface hardness after PEO treatment, compared to the untreated samples. The major advantages of PEO include lower energy consumption, high quenching rates, and the ability to perform localised surface treatments. These benefits contribute to overall cost reduction, making PEO a promising surface hardening method for various industrial applications.

Tests and analysis of the results of the mechanical properties of various aluminium alloys

Abstract It is essential to know the mechanical properties of a material used in a structure to determine its purpose and lifespan. These properties largely depend on the material’s creation process and chemical composition. The verification of mechanical properties is done by performing standard test methods. These tests confirm if the material’s characteristic properties stated in certificates and other documents from the supplier are accurate. This paper explains the procedure of experimental testing of different aluminum alloys through tensile tests using standard test tubes made of three types of alloys - EN AW 5083, EN AW 6082, and EN AW 7075. The test results are shown diagrammatically as the elongation-stress dependence and the values of the fundamental mechanical properties were read. The methodology of experiments according to the standards for this type of test was covered, and finally, the analysis and comparison of the results obtained were performed depending on the type of material.

Atomic Interaction S. aureus/Machined and Additive Manufacturing Ti-6Al-4V and Ti-35Nb-7Zr-5Ta Disks for Dental Implants.

The adhesion strength of a bacterial strain on a substrate influences colonization and biofilm development, so the biomolecular analysis of this interaction is a step that allows insights into the development of antifouling surfaces. As peri-implantitis is the main cause of failure of implant-supported oral rehabilitations and the dental literature presents gaps in the atomic bacteria/surface interaction, this study aimed to correlate the qualitative variation of roughness, wettability, chemical composition, and electrical potential of Ti-6Al-4V and Ti-35Nb-7Zr-5Ta (TNZT) disks obtained by machining (M) and additive manufacturing (AM) on the colonization and adhesion strength of S. aureus quantified by atomic force microscopy (AFM). The samples were evaluated for roughness, electrical potential, and S. aureus colonization and adhesion strength by specific methods in the AFM with subsequent analysis in the NanoScope software analysis, wettability by sessile drop method, and chemical composition by energy dispersive x-ray spectroscopy (EDX). Qualitative data were correlated with bacterial adhesion strength. The greater adhesion strength of S. aureus was observed in descending order for TNZT AM, TNZT M, Ti-6Al-4V AM, and Ti-6Al-4V M. This experimental invitro study allowed us to conclude that for the evaluated groups, the strength adhesion of S. aureus showed a linear relationship with roughness, and nonlinear for wettability, electrical potential, and S. aureus colonization on the surfaces evaluated. As for the two variation factors, type of alloy and manufacturing method, those that promoted the lowest bacterial adhesion strength were Ti-6Al-4V and M, possibly attributed to the synergistic modification of the evaluated surface properties. Thus, this study suggests S. aureus preferences for rough, hydrophilic surfaces with a greater electrical potential difference.

Etidronic Anodizing of Aluminum Alloys: Growth and Properties of Anodic Layers

Anodizing is a well-known electrochemical process used to increase the thickness of the natural oxide present on the surface of aluminum alloys. This process is commonly employed to enhance properties such as anticorrosion and hardness. Sulfuric acid is the most frequent used electrolyte for aluminum alloy anodizing, offering significant corrosion resistance. For applications requiring a hard anodic layer, a specialized sulfuric anodizing can be implemented, where the bath temperature is around 0°C. However, when anodizing is necessary at room temperature, Huang et al. [1] have suggested the use a new electrolyte: etidronic acid (HEDP). The present work focuses on the study of this new hard anodizing process, with etidronic acid. Electrochemical analyses as well as anodic layer characterizations have been performed for various aluminum alloys including 1050, 2024 and 7075 alloys. The growth of the anodic layer varies depending on the alloy type. Two modes of anodization have been identified: a conventional anodization mode (for 1050 alloy) and a second mode which can be considered as micro-arc anodization (for 2024 et 7075 alloys). These anodization regimes will induce modifications in the thickness, morphology, crystallinity, and hardness of the anodic layers.[1] H. Huang, J. Qiu, X. Wei, E. Sakai, G. Jiang, H. Wu, T. Komiyama, Ultra-fast fabrication of porous alumina film with excellent wear and corrosion resistance via hard anodizing in etidronic acid, Surface & Coatings Technology 393 (2020) Figure 1

Interfacial Electrochemistry and Mechanics of Carbon Interlayers for Anode-Free Solid-State Batteries

Solid-state batteries provide a promising alternative to Li-ion batteries with improved energy density, safety, and manufacturability. However, anode-free cell configurations still suffer from multiple shortcomings, including 1) nonuniform Li deposition and dissolution, 2) continual formation of a solid-electrolyte interphase (SEI), and 3) limited rate capability. Recent efforts have investigated the integration of a carbon/silver composite interlayer to address the aforementioned challenges [1]; however, complete understanding of the mechanisms of this improved performance is not fully understood. The type of carbon, metal alloy, and lithiation effects of these components have been investigated [2,3], particularly, the electrochemical characteristics, but the mechanical properties of these interlayers have not been thoroughly investigated. Therefore, in this study we explore the interfacial mechanics at an amorphous carbon interlayer and argyrodite solid electrolyte interface on in situ Li metal formation.The carbon interlayer and solid electrolyte interfacial adhesion were modified to investigate the corresponding influence on Li metal deposition. Peel tests are performed to quantify the interlayer adhesion under various processing conditions. Li metal was observed to preferentially deposit at regions with the lowest energy penalty for nucleation and growth. By intentionally tuning the carbon/solid electrolyte interface, the growth of Li metal can be promoted at different interfaces. Operando video microscopy and post-mortem focused ion-beam/scanning electron microscopy were utilized to confirm the Li deposition behavior. This work demonstrates that Li deposition in the presence of a carbon interlayer can be systematically modified by tuning the interfacial mechanics. The outcomes of this study will further our understanding of the processing conditions and underlying mechanics during in situ Li metal formation to enable high efficacy interlayers in solid-state batteries.[1] Y.G. Lee, S. Fujiki, C. Jung, N. Suzuki, N. Yashiro, R. Omoda, D. S. Ko, T. Shiratsuchi, T. Sugimoto, S. Ryu, J. H. Ku, T. Watanabe, Y. Park, Y. Aihara, D. Im, I. T. Han, Nature Energy. 5, 299-308 (2020)[2] D.W. Liao, T.H. Cho, S. Sarna, M.K. Jangid, H. Kawakami, T. Kotaka, K. Aotani, N.P. Dasupta, Journal of Materials Chemistry A, 12, 5990-6003 (2024)[3] N. Suzuki, N. Yashiro, S. Fujiki, R. Omoda, T. Shiratsuchi, T. Watanabe, Y. Aihara, Advanced Energy and Sustainability Research, 2, 2100066 (2021)

Electropolishing of Magnesium and Its Alloys in Highly Safe Sodium Chloride/Glycol Solutions

Magnesium and its alloys are expected to be used in various engineering fields, such as automobiles, trains, and electronic product enclosures due to their lightness and mechanical properties. Electropolishing of magnesium surfaces is an important technique for fundamental research works and industrial applications, and perchloric acid or nitric acid is typically used for electropolishing. However, these acids are highly reactive and hazardous, thus the usage should be avoided in the industrial application processes. In this study, we demonstrated a highly safe electropolishing process of magnesium using a novel sodium chloride/glycol solution.High-purity magnesium plates (99.95 wt%, 1 mm thick) were used as the starting materials. The specimens were ultrasonically degreased in ethanol for 10 min. The magnesium specimen as the anode and a platinum plate as the cathode were immersed in four types of glycol solutions including 0.5 M NaCl/ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TrEG), and tetraethylene glycol (TeEG) solutions at 278-308 K, and linear sweep voltammetry (0.1 Vs-1) and constant voltage electrolysis (25-100 V) were carried out. After electrolysis, the surface of the specimens was examined by stereo microscopy (SM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The regular reflectance from the magnesium surfaces was measured using a spectrophotometer. Two types of industrial magnesium alloys including Mg-Al alloy, AZ31, and Mg-Li alloy, LZ91, were also used for electrolysis.As the voltage-current curves were measured by linear sweep voltammetry of the pure magnesium specimen in four types of glycol solutions, clear diffusion limiting currents were obtained after the initial current increases. We found that the unevenness of the magnesium specimens decreased by constant voltage electrolysis at appropriate applied voltages in NaCl/DEG and NaCl/TeEG solutions. Figure 1a shows the surface appearances of pure magnesium, LZ91, and AZ31 after constant voltage electrolysis at 50 V in NaCl/DEG solution for 60 min. The pure magnesium specimen and LZ91 alloy were successfully electropolished by constant voltage electrolysis and mirror-finished surfaces were obtained. On the other hand, the AZ31 alloy exhibited a nonuniform appearance with the coexisting of metallic luster and brownish regions, although a mirror-finished surface was obtained. The difference of the electropolishing behaviors between LZ91 and AZ31 alloys may be due to the metallographic structure such as the solid solution and intermetallic compound. Three-dimensional magnesium specimens possessing the curved and spiral structures could also be electropolished by constant voltage electrolysis in NaCl/DEG (Fig. 1b). Figure 1

Integration of confocal chromatic spectroscopy into a test bench concept for safety inspection practices, with focus on stress detection

Evaluating casting’s mechanical stress is of significant interest from a safety inspection’s point of view. Residual stress, in particular, leads to an early or even immediate failure of some parts. Therefore, several methods exist to determine casting’s external and internal strain leading to stress. By determining the state of stress and residual stress, it is possible to design casting parts that are much safer. The present concept of a test bench shows a new way of inspecting parts for safety reasons using an optical fiber confocal chromatic sensor to measure strain. The method is based on the deep-drilling method, where a minimal invasive hole is placed at an area of interest in the first step. In a second step, this hole is then precisely measured to be able to map the borehole. From this information, conclusions can be drawn of any forces acting on the inspected part. In this case, the concept of the test bench uses gun drills to place boreholes measuring 6.0 mm in diameter with up to 500.0 mm in depth, and for the inspection, a confocal sensor with a precision of ± 100.0 nm in dissolving distances is used. This work focuses on evaluating the test bench’s precision in conducting such measurements and on how an external thermal load and mechanical load influence the results when conducting differential measurements. The experiments are performed on typical cast alloys such as iron cast and Zamac.

Temperature effects on low cycle fatigue deformation of powder metallurgy superalloy FGH95

The macroscopic morphology and microstructure evolution mechanism of the FGH95 alloy were investigated with regard to fracture under low-cycle fatigue at different temperatures. The fracture modes of the FGH95 alloy at 420 °C, 510 °C, and 600 °C were found to fall into two main categories: shear fracture at low temperatures (420 °C, 510 °C) and I type fracture at high temperatures (600 °C). The change in fracture mode can be attributed to the increase in strength of the precipitated phase with temperature. At low temperatures, the dislocation structure moves mainly by cutting, bypassing the precipitated phase by climbing at high temperatures. The different movement of the dislocations leads to the different fracture types of FGH95 alloy at different temperatures.

Experimental investigation and thermodynamic calculation of the Al-Cr-Pd ternary system

The phase relations of the Al-Cr-Pd ternary system above 1100 °C and the thermodynamic description were lacking to guide the compositional design of the Cr and Pd co-modified aluminide coating. Herein, the isothermal section of the Al-Cr-Pd ternary system at 1150 °C was experimentally determined through scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and X-ray diffraction. In addition, a thermodynamic description of the ternary system was established by the application of CALPHAD (CALculation of PHAse Diagrams) technique based on the experimental results of the isothermal section at 930, 970, 990, 1020 and 1150 °C. The solidification paths of typical alloys determined in the previous literature were also fitted. A set of self–consistent thermodynamic parameters for the Al-Cr-Pd ternary system was obtained with a reasonable agreement between the experimental and calculated results. The results provide a basis for the compositional design of aluminide coatings and enrich the Al-based database.

The diversity of evolution behavior between stoichiometric and non-stoichiometric AlTM intermetallics in Mg melt

In this study, Al-5Ti, Al-18Si-5Ti, Al-12Si-2Sc and Al-12Si-1Sc-1Zr alloys, containing the Al3Ti, Ti7Al5Si12, AlSi2Sc2 and AlSi2(Sc, Zr)2 particles, respectively, were introduced into a Mg melt to understand the morphological and structural evolution behaviors of AlTM intermetallic compounds. Deposition layers at the bottom of the Mg melt were obtained due to the particle settlement. Scanning electron microscope and X-ray diffraction were employed to analyze the phase morphologies and structures of the AlTM intermetallic compounds in the deposition layers. A morphological transformation, characterized by the cracking of particles into fine clusters, was observed in all these AlTM intermetallic compounds, which is promoted by the inward diffusion of Mg atoms. The phase structures of the final particles remained Al3Ti and AlSi2Sc2 when Al-5Ti and Al-12Si-2Sc alloys were introduced into the Mg melt, indicating no structural evolution. However, structural evolutions were detected from Ti7Al5Si12 to Ti5Si4 and from AlSi2(Sc, Zr)2 to SiScZr when they were introduced in the Mg melt. It is hypothesized that the crystal structure, whether stoichiometric or non-stoichiometric, is closely related to the structural evolution behavior of AlTM intermetallic compounds. This work may provide new insights into phase control by introducing one type of metal matrix master alloy into another metal melt.

Integrating sustainability into material design and selection through eco-design: A case study on aluminum alloy plates

Traditional material design focuses primarily on performance, properties, structure, and synthesis. Growing environmental awareness necessitates the integration of sustainability considerations into material design and selection. This paper introduced an approach that embeds the eco-design method within material comparison to balance performance requirements and environmental sustainability. Five types of aluminum alloys were examined to demonstrate and validate the proposed method. The alloys are commonly used in shipbuilding and have varying contents of the rare earth element Erbium. The alloys were assessed through a performance-requirement matrix, life cycle assessment, and exergy calculation to evaluate their performance, environmental impact, and resource consumption. A binary integrated decision model was created to compare the five alloys based on either their performance and environmental impact or their performance and resource consumption. Additionally, ternary integrated decision models were formulated to yield a comprehensive analysis of the five alloys, considering all three aforementioned factors. A matrix model was established to allow for comparative assessment no matter how many indicators are involved. Furthermore, a model based on the enumeration method was presented to mitigate the bias introduced by weighting factors. This methodological approach aids in selecting the most suitable alloys for diverse scenarios, thereby enhancing the sustainability of material design.

Corrosion evaluation of Al-Cu-Mn-Zr cast alloys in 3.5% NaCl solution

Corrosion behavior of cast Al-Cu-Mn-Zr (ACMZ) and RR350 alloys was compared to a cast 319 alloy in 3.5 wt.% NaCl. After 168 h immersion, ACMZ and RR350 alloys suffered from preferential attack adjacent to intermetallic particles decorated at grain boundaries while the attack in 319 occurred in eutectic Al-Si dendritic boundaries. Electrochemical data allowed semiquantitative comparison of alloy resistance to corrosion initiation, and ACMZ type alloys, including RR350 and three alloys with higher Cu, were considered more resistant than 319 due to the absence of deleterious Si particles. In case of 319, such Si particles presumably drove higher micro-galvanic influence to initiate and sustain Al corrosion. With lower susceptibility to corrosion initiation, ACMZ alloys should exhibit higher or at minimum similar resistance compared to cast 319.