Effect Of Cu Content Research Articles

Effects of Cu content on microstructures and compressive mechanical properties of CNTs/Al-Cu composites

The carbon nanotubes (CNTs) reinforced Al-Cu matrix composites were prepared by hot pressing sintering and hot rolling, and the effects of Cu content on the interfacial reaction between Al and CNTs, the precipitation behavior of Cu-containing precipitates, and the resultant mechanical properties of the composites were systematically investigated. The results showed that the increase of Cu content can not only increase the number and size of Cu-containing precipitate generated during the composite fabrication processes, but also promote the interfacial reaction between CNTs and Al matrix, leading to the intensified conversion of CNTs into Al4C3. As a result, the composite containing 1 wt.% Cu possesses the highest strength, elastic modulus and hardness among all composites, due to the maintenance of the original structure of CNTs. Moreover, the increase of Cu content can change the dominant strengthening mechanisms for the enhanced strength of the fabricated composites.

Mechanical properties and frictional behavior of SiCp/Al-Si-Cu-Ni-Mg hybrid composites at an elevated temperature

PurposeThis paper aims to investigate the effect of Cu content and T6 heat treatment on the mechanical properties and the tribological performance of SiCp/Al-Si-Cu-Ni-Mg hybrid composites at an elevated temperature.Design/methodology/approachThe stir casting method was used to synthesize SiCp/Al-12Si-xCu-1Ni-1Mg (x = 2, 3, 3.5, 4, 4.5, 5 Wt.%) composites containing 20 vol% SiC. The hardness and tensile strength of the aluminum matrix composites (AMCs) at room temperature and elevated temperature were studied, and the wear mechanism was investigated using scanning electron microscopic and energy dispersive spectroscopy.FindingsResults indicate that the hardness and tensile strength of the AMCs are affected significantly by T6 heat treatment and Cu content. The high-temperature friction and wear mechanism of AMCs is the composite wear mechanism of oxidation wear, adhesion wear, abrasive wear, peeling wear, high-temperature softening and partial melting. Among them, adhesion wear, high-temperature matrix softening and local melting are the main wear mechanisms.Originality/valueThe influence mechanism of Cu content on the hardness, tensile strength and high temperature resistance of AMCs was explained by microstructure. And the results further help to explore the application of AMCs in high temperature.

Effect of Cu content on microstructure and properties of CoCrFeNiCux high-entropy alloy coatings prepared by induction cladding

CoCrFeNiCux (x = 0, 0.5, 1.0, 1.5) high entropy alloy coating (HEAc) on Q235 steel was successfully prepared by induction cladding technology. Before induction cladding, the final structure of the alloy powders after 30 h ball milling were single-phase face-centered cubic (FCC) structure. After induction cladding, the metastable Cu-containing alloy powders were transformed into a stable dual-phase, that was, Cu-depleted FCC1 and Cu-rich FCC2. It was worth noting that HEAc exhibited a hardness gradient from top to bottom due to the unique principle of induction cladding. With the increase of Cu content, the grain size of HEAc was refined, but the overall hardness and wear resistance of HEAc decreased due to the precipitation of Cu. Grain refinement also provided more channels for oxygen invasion, and the oxidation resistance decreased. The convergence of Cu element at grain boundaries led to local galvanic corrosion, which greatly reduced the corrosion resistance. Therefore, the precipitation of Cu and grain refinement had great influence on the wear resistance, high temperature oxidation resistance and corrosion resistance of HEAc.

Effects of biochar on the dynamic immobilization of Cd and Cu and rice accumulation in soils with different acidity levels

The aim of this study was to investigate the effect of biochar on Cd and Cu immobilization and bioavailability in soils with different acidity levels. Four dosages (0, 20, 40 and 60 g kg−1; namely CK, C1, C2 and C3) of biochar produced from rice straw were applied into the soils with four acidity levels (pH 4.5, 5.0, 5.5 and 6.0; namely L1, L2, L3 and L4), the uptake and transport of Cd and Cu by rice and metal speciation dynamics in soil were investigated through the two-year pot experiment. The soil pH and organic matter under all the four acidity levels were significantly increased during the rice maturity stage in the second year after biochar application. Biochar mainly promoted the formation of oxidizable Cd, followed by reducible Cd, and decreased residual Cd content (except for the first-year in the jointing period) during the two consecutive years of rice growth. Biochar reduced the acid extractable Cu content (especially in L2 and L3), increased the oxidizable Cu content, and interconverted Cu between reducible and residual status. The content of Cd in different rice organs were reduced by biochar, and compared with CK, the two-year average reduction in brown rice was 38.12%, 58.07%, 50.99% and 36.45% under L1, L2, L3 and L4. The reduction effect of Cu content in brown rice by biochar was mainly reflected in the second year, which decreased by 17.52%, 20.17%, 20.63% and 9.74% respectively under the four acidity levels. Rice straw biochar can be used for Cd pollution control of rice grain in paddy soil with varied acidity levels. However, further studies are needed on how biochar promotes Cu transport from rice root to shoot.

Effect of Cu Content on Microstructure and Mechanical Properties for High-Strength Deposited Metals Strengthened by Nano-Precipitation

With the rapid development of low-carbon high strength steel, higher requirements are put forward for the matching welding consumables. The deposited metals with 0.62–2.32% Cu addition was prepared by tungsten inert gas welding via metal cored wire. The effect of Cu element on microstructure and mechanical properties of deposited metals were investigated. The multiphase microstructure of deposited metals consists of bainite, martensite, residual austenite, and martensite-austenite constituents. It is found that Cu decreases the start temperature of martensite (Ms) and enlarges the temperature range of bainite from 372 K to 416 K, improving the formation of bainite. With the increase of Cu content, the fraction of martensite decreases and the shape of M-A constituents changes from strip into granular. There are BCC and FCC Cu precipitates in deposited metals. The diameter of Cu precipitates is 14–28 nm, and the volume fraction of it increases with the increase of Cu content. Meanwhile, the deposited metals with 1.79% Cu can achieve a 10% enhancement in strength (yield strength, 873–961 MPa, ultimate tensile strength, 1173–1286 MPa) at little expense of impact toughness (64.56–56.39 J at −20 °C). Cu precipitation can effectively improve the strength of the deposited metals, but it degrades toughness because of lower crack initiation energy. The deposited metal with 1.79% Cu addition shows an excellent strength-toughness balance.

Effects of Cu content in Al-Cu alloys on microstructure, adhesive strength, and corrosion resistance of thick micro-arc oxidation coatings

In this work, effects of Cu content from 1 to 4.5 wt. % on morphologies, phase composition, and residual stress of micro-arc oxidation (MAO) coatings on Al-Cu alloys at the oxidation of 40 min were investigated. Furthermore, the adhesive strength (AS) and corrosion resistance of the MAO coatings were evaluated. The MAO coatings were characterized by SEM, XRD, and laser scanning confocal microscope. The MAO coating on the Al-1Cu alloy showed the low porosity (6.0 %), high AS (20 N), and excellent corrosion resistance. The corrosion behavior of the MAO coating on the Al-3Cu alloy was poor due to the high porosity. The results indicated that the thermal conductivity of the substrate affected the micropores and residual stress of the MAO coatings. The AS of the MAO coating on the Al-3Cu alloy was 15 % lower than that on the Al-1Cu alloy. The residual compressive stress, high hardness, and low porosity contributed to the excellent adhesion. In addition, the simultaneous occurrence of residual tensile stress and compressive stress in the coatings on the Al-1Cu and Al-4.5Cu alloys were attributed to the inhomogeneous distribution of micropores.

Effect of Cu content on microstructure evolution and tribological behaviors of Ni60 composite coatings on 45# steel by laser cladding

The Ni60-Cu composite coatings with varying Cu contents were fabricated by laser cladding technology. The effects of Cu addition on the microstructure, microhardness, and tribological behaviors were explored systematically. The results revealed that the composite coatings were primarily consisted by γ-Ni, FeNi3, Cr7C3, Ni3Si, Cu, and Fe-Ni-B. The addition of Cu was instrumental in enhance the tribological behavior at room temperature and 600 °C compared with the 45# steel substrate. Moreover, S2(Ni60-5 %Cu) coating showed the best compressive tribological properties, especially at 600 °C, it has the lowest friction coefficient of 0.267 and wear rate of 4.90 × 10-5mm3/N·m. The Cu played the role of tribo-transfer film and oxidation double-layered self-lubricant at room temperature and 600 °C, respectively.

Investigation of glass forming ability, crystallization behavior, and soft magnetic properties of Fe–B–P–C–Cu alloy ribbons

The effect of Cu content on GFA, crystallization behavior, and soft magnetic properties in high P Fe84+xB6P6C3Cu1−x (x = 0, 0.2, 0.4, 0.6, and 1.0 at. %) alloy ribbons were systematically investigated to balance the relationship between glass forming ability (GFA), heat treatment window, and soft magnetic properties of high saturation magnetic flux density (Bs) Fe-based nanocrystalline alloys. It was discovered that lowering Cu promotes the formation of an amorphous structure. The GFA of alloys rises from 23 μm for Fe84B6P6C3Cu1 to 29 μm for Fe84.4B6P6C3Cu0.6. Analysis of thermal physical properties shows that when Cu content is between 1.0 at. % and 0.6 at. %, reducing Cu in the alloys does not affect the onset temperature of the first crystallization peak (Tx1), the second one (Tx2), and ΔT (ΔT = Tx2 − Tx1), whereas when Cu content is less than 0.6 at. %, reducing Cu leads to an increase in Tx1 and a decrease in Tx2 and ΔT, which is not conducive to obtaining a wide temperature range of precipitation of a single α-Fe phase. The alloys have a wide range of crystallization annealing temperature (693–753 K) and annealing time (60–6 min) to obtain a low coercivity (Hc) of about 8.0 A/m, high Bs of about 1.80 T, and high effective magnetic permeability (μe) of about 10000 when Cu is between 1.0 at. % and 0.6 at. %. The Bs, Hc, and μe of Fe84.4B6P6C3Cu0.6 alloy annealed at 723 K for 30 min are 1.82 T, 8.1 A/m, and 10820, respectively.

Effect of Ti–Cu alloy's composition on microstructure and performance of carbon fiber reinforced TiC-based composites prepared by alloyed reactive melt infiltration

In order to improve the strength and toughness of ceramic matrix composites, carbon fiber reinforced TiC-based composites modified with Cu based alloys were fabricated by alloyed reactive melt infiltration method using Ti27Cu73, TiCu and Ti2Cu alloys as infiltrators. The effects of Cu content on the composite's microstructure, mechanical strength and tribological properties were respectively investigated. The as-produced composites were mainly composed of C, TiC, Cu and Ti–Cu phases. With the decrease of Cu content in the infiltrated alloys, more TiC matrix was produced in the composites. The composites prepared with the infiltrators with high Cu contents exhibited enhanced mechanical properties. The composites prepared by Ti27Cu73 alloy owned the largest strength of 294.73 ± 23.91 MPa, while the composites prepared by TiCu alloy had the best fracture toughness of 14.36 ± 1.42 MPa m1/2. The as-produced composites exhibited good wear resistance. A Cu based friction layer was observed on the friction trace due to the introduction of Cu based alloy matrix into the composites, which greatly improved the abrasive performance.

Al/Cu-PILC as a Photo-Fenton Catalyst: Paracetamol Mineralization.

Pillared clays have shown to effectively catalyze the photo-Fenton process without the necessity of acidic conditions, which is a very attractive feature from the perspective of environmentally friendly processes, especially when high natural abundance of chemical elements are incorporated. In this work, the catalytic activity of Al/Cu interlayered pillared clays for the degradation and mineralization of paracetamol through a photo-Fenton-like process was investigated. Al/Cu-pillared clays were prepared by adding ane Al/Cu pillaring solution to a bentonite suspension. X-ray diffraction (XRD) confirmed the enlargement of the interlayer space of the clay provoked by the pillaring process and Al and Cu species in the prepared samples were verified by atomic absorption spectroscopy (AAS). The specific surface area of pure bentonite was 2-fold increased after the Al/Cu pillaring process. A synthetic paracetamol solution with an initial concentration of 100 ppm was prepared for the assessment of the activity of the prepared materials. Different catalyst concentrations were tested (0.2, 0.5, 0.75, and 1 g L–1) and the complete removal of paracetamol was achieved in all cases, but the highest mineralization rate (69.8 mg total organic carbon (TOC) gcat–1 h–1) corresponds to the catalyst loading of 0.5 g L–1. An ultraviolet-C (UVC) light source was employed, and no adjustment of the pH to acidic conditions was needed to achieve these results. Liquid chromatography coupled to mass spectroscopy (LC-MS) was employed to identify the reaction intermediates of paracetamol degradation. A proposed pathway for the oxidation of paracetamol molecule is presented. The effect of Cu content in the pillared clay and the stability and reusability of the catalyst were also assessed. The kinetic constants of paracetamol removal were 0.2318 and 0.0698 min–1, under photo-Fenton and UV + H2O2 processes, respectively.

Effects of Cu content on microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys

A systematic study on how Cu content affects the microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys during solution treatment and ageing heat treatment was conducted. The swirled enthalpy equilibrium device (SEED) was adopted to prepare the semi-solid slurry of Al-6Zn-2Mg-xCu alloys. The microstructure development and mechanical properties were studied using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), as well as hardness and tensile testing. The grain boundary and shape factor were calculated using image processing software (Image-Pro Plus 6.0). Results show that the alloys are composed of typical globular primary α-Al grains, eutectic phases, and smaller secondary α-Al grains. After solution and ageing heat treatment, the eutectic phases are dissolved into Al matrix when the Cu content is lower than 1.5wt.%, while some eutectic phases transform into Al2CuMg (S) phases and remain at grain boundaries when Cu content reaches 2wt.%. T6 heat treatment significantly enhances the mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys. When Cu concentration is 0.5wt.%–1.5wt.%, the ultimate tensile strength, yield strength and elongation of T6 treated alloys rise to around 500 MPa, 420 MPa, and 18%, respectively.

Effect of Cu content and Zn/Mg ratio on microstructure and mechanical properties of Al–Zn–Mg–Cu alloys

Al–Zn–Mg–Cu alloys were fabricated with water-cooled copper casting. The microstructure of the alloys was characterized by electron probe microanalysis (EPMA), scanning electron microscope (SEM), transmission electron microscopy (TEM), and X-ray diffractometry (XRD). The mechanical properties were studied with by tensile and hardness tests. The results showed an enhanced effect of solid solution strengthening and precipitation strengthening with increased Cu content. The distribution spacing of the grain boundary precipitates (GBPs) increased, but the width of the precipitate-free zone (PFZ) decreased. The process enhanced the strength and plasticity of the alloy. The impact of precipitation strengthening decreased and the grain size and width of the PFZ decreased as the Zn/Mg ratio increased. Thus, the strength of the alloy decreased and its plasticity increased with increasing Zn/Mg ratios.

Effect of Cu Content on the Microstructures of As-Cast and Homogenized Al-Cu-Mg-Ag Alloys

The microstructures of as-cast and homogenized Al-Cu-Mg-Ag alloys with 1.98, 3.66 and 5.16 wt.% Cu contents (Alloy 1, Alloy 2, Alloy 3, respectively) were investigated by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and calculation of phase diagram. The results indicate that the second phases in the as-cast alloys consist of θ (Al2Cu), ternary α (Al)-θ (Al2Cu)-S(Al2CuMg) eutectic and Fe-enriched phase. The invariant reactions are L→α (Al) + θ (Al2Cu) at 542°C and L→α (Al) + θ (Al2Cu) + S(Al2CuMg) at 505°C during solidification. An increase of Cu content promotes the formation of θ (Al2Cu) phase, therefore leading to the total second phases increasing in the as-cast alloys. The ternary eutectic completely dissolves into the matrix after the first-step homogenization at 490°C, and θ (Al2Cu) phase dissolves subsequently after the second-step homogenization at 510°C. It is suggested that the proper homogenization treatments are 490°C/24 h for Alloy 1, 490°C/24 h + 510°C/24 h for Alloy 2 and 490°C/24 h + 510°C/48 h for Alloy 3.

Effect of Cu content on the precipitation behavior of Cu-rich and NiAl phases in steel

The nanoscale precipitation and the mechanical properties of the two CuNiAl-containing steels with different Cu contents aged at 500 °C were investigated in this study. Results of mechanical property indicated that the co-precipitation of Cu-rich and NiAl phases during aging contributed to the precipitation strengthening effects. The influence of Cu content on the evolution of precipitates was studied by atom probe tomography (APT). The results demonstrated that the increasing of Cu content enhanced the number density of precipitates and accelerated the precipitation process. The two steels showed two kinds of precipitation sequences on account of different Cu contents. The steel 1 with low Cu content exhibited a precipitation sequence of “supersaturated solid solution → NiAl → NiAl + Cu”, while the steel 2 with high Cu content presented the process of “supersaturated solid solution → Cu → Cu + NiAl”. After further aging, the precipitates of both steels were transformed into Cu/NiAl co-precipitates without isolated Cu-rich phases and isolated NiAl phases. • Hardness of the CuNiAl-containing steel can be improved by increasing the Cu content. • The increasing of Cu content enhances the number density of precipitates and accelerates the precipitation process. • The precipitation sequences of two steels with different Cu contents are clarified.

Influence of Cu content on the microstructure and mechanical property of Ti3SiC2/Cu composites

Ti3SiC2/Cu composites with different Cu content were prepared by spark plasma sintering (SPS) process in vacuum and the effect of Cu content on the microstructure and mechanical property was investigated. The axial displacement, temperature and current of the composites during the sintering process were recorded and discussed. The phase compositions of the original Ti3SiC2 and Cu powder before and after ball-milling, and the as-produced composites were studied by XRD analysis. The surface morphology and fracture surface of the composites were investigated by SEM. The influence of Cu content on the relative density, hardness and compressive strength of the composites was inquired. The results discovered that the phase composition of Ti3SiC2/Cu composites varied with the content of Cu. The phase composition of the Ti3SiC2/5 vol% Cu composite was composed of Ti3SiC2, Ti5Si3 and Cu3Si, while that of Ti3SiC2/10 vol% Cu composite and Ti3SiC2/15 vol% Cu composite contained TiC, besides Ti3SiC2, Ti5Si3 and Cu3Si. Moreover, the relative density of all Ti3SiC2/Cu composites was relatively high (≥93%). With the increase of Cu content, the axial displacement, hardness and compressive strength of the Ti3SiC2/Cu composites increased. Conclusively, the Ti3SiC2/Cu composite with 15 vol% Cu exhibited better mechanical properties.

Effect of Cu on the Microstructure of Al-8Zn-2.5Mg-xCu Alloys Fabricated by Twin roll casting

The effect of Cu content on the microstructure and mechanical properties of Al-8.0Zn-2.5Mg-xCu (x: 0, 1, 2, 3) aluminum alloys manufactured by the twin-roll casting process was investigated. The Al-8.0Zn-2.5Mg-xCu alloy showed an increase in surface defects with increasing Cu content. This is because the amount of residual liquid in the final solidification region increased from 9.6 wt.% to 18.3 wt.% as the Cu content increased from 0Cu to 3 Cu alloy. For the 3Cu alloy, as the amount of residual liquid in the final solidification region exceeded the critical point, a large number of surface defects and internal shrinkage defect were observed. The main secondary phases of the four alloys were the T(Mg32(Al, Zn)49) and η(MgZn2) phases, and their fraction increased with Cu content. These secondary phases mainly existed in the center segregation band, and a fine η(MgZn2) phase was additionally observed. In terms of mechanical properties, as the Cu content increased, the hardness of the center matrix, secondary phase, and overall hardness increased respectively. Although the yield strength increased, the tensile strength and elongation decreased because the center segregation band was widened from 684 μm to 790 μm with increasing Cu content.

Influence of Cu content on microstructure, grain orientation and mechanical properties of Sn–xCu lead-free solders

The effect of Cu content on the microstructure, grain orientation and mechanical properties of Sn–xCu (x=0–4.0 wt.%) lead-free solder was studied. Results showed that added Cu induced the formation of intermetallic phases. Only the η-Cu6Sn5 and ɛ-Cu3Sn phases were present in the β-Sn matrix. For all contents, the strongly preferred orientation of the β-Sn phase was formed on the {001} plane. In Sn doped with 1.0 wt.% Cu, the η-Cu6Sn5 phase exhibited the preferred orientation of {0001} plane, whereas doping with 3.0 or 4.0 wt.% Cu transformed the preferred orientation to the {010} plane. In addition, only the {0001} and planes were present in the ɛ-Cu3Sn phase. The high Cu contents contributed to an increased number of low-angle boundaries, high residual strain, tensile strength and microhardness.

Effect of Cu Content on the Precipitation Behaviors, Mechanical and Corrosion Properties of As-Cast Ti-Cu Alloys.

Ti-Cu alloys have broad application prospects in the biomedical field due to their excellent properties. The properties of Ti-Cu alloys are strongly dependent on Cu content, microstructures, its Ti2Cu phase and its preparation process. The aim of this work is to investigate the effect of Cu content on the precipitation behaviors, mechanical and corrosion properties of the as-cast Ti-Cu alloys. The microstructures and phase evolution were characterized by SEM and TEM, and the properties were studied by tensile and electrochemical test. The results show that the volume fraction of Ti2Cu phase increases with the increase of Cu content. The Ti2Cu phase presents a variety of microscopic morphologies with different Cu content, such as rod, granular, lath and block shaped. The crystal orientation relationships between the Ti2Cu and α-Ti matrix in Ti-4Cu and Ti-10Cu alloys are (103)Ti2Cu//(0[111)α-Ti, [01]Ti2Cu//[20]α-Ti, and (103)Ti2Cu//(0002)α-Ti, [31]Ti2Cu//[110]α-Ti, respectively. The tensile strength, Vickers hardness and Young’s modulus of the Ti-Cu alloys increase with the increase of Cu content, whereas the elongation decreases. The fracture morphologies of these alloys reveal ductile, ductile-brittle hybrid, and cleavage brittle mode, respectively. The corrosion resistance of the Ti-Cu alloys in SBF solution can be described as: Ti-4Cu alloy > Ti-10Cu alloy > Ti-7Cu alloy. The volume fraction of Ti2Cu phases and the “protective barrier” provided by the fine lath Ti2Cu phases strongly affected the electrochemical performances of the alloys.

Effect of Cu Content on Structure of NiCu Alloy Catalyst and Catalytic Performance for Nitroarenes Hydrogenation

AbstractCarbon doped silica‐supported NiCu alloy nanoparticles (Ni1Cux/C@SiO2) with different Cu/Ni molar ratio (x=0.12, 0.24, 0.36) were fabricated via one‐step impregnation, following in situ carbonization reduction. Effects of Cu content on catalyst structure, surface properties and particle sizes were investigated by Brunauer‐Emmett‐Teller (BET), inductively coupled plasma (ICP), Raman, X‐ray diffraction (XRD), transmission electron microscopy (TEM) and X‐ray photoelectron spectroscopy (XPS). The surface Ni0 content increased with increasing Cu content, but showed a maximum at 0.24 of Cu/Ni molar ratio, because the smaller NiCu alloy nanoparticle formed and the segregation of antioxidative Cu atoms on the surface protected the metallic Ni from oxidation. The Ni1Cux/C@SiO2 were investigated for nitrobenzene hydrogenation with H2. The optimal Ni1Cu0.24/C@SiO2 catalyst with the highest Ni0 content showed markedly improved catalytic activity compared to monometallic Ni/C@SiO2. The Ni0 species were the active sites for the hydrogenation of nitrobenzene. The Ni1Cu0.24/C@SiO2 could transform various substituted nitroarenes to corresponding aromatic amines. Moreover, the Ni1Cu0.24/C@SiO2 could be recycled for 8 times without decrease in catalytic performance, exhibiting superior anti‐oxidation and anti‐leaching abilities.

High temperature oxidation properties of Al-Cu-Si alloys for latent heat energy storage

The effect of Cu content on the high temperature oxidation properties of the phase change material (PCM) Al-Cu-Si alloys was studied. The oxidation kinetics curves at 600℃ were achieved for Al-Cu-Si alloys with 35–55% Cu, which all follow the cubic law. With an increase in the Cu content from 35 to 55%, the weight gain decreases from 5.75 to 3 × 10−4 g/cm2 after 96 h isothermal oxidation. The oxidation rate also decreases with Cu content, the maximum and minimum rates are 1.52 and 0.32×10−5 g/cm2•h, a nearly 4 times difference. Oxidation does not change the phase composition of Al-Cu-Si alloys, but coarsens the microstructure. The latent heat and the starting temperature of phase change after 96 h oxidation at 600℃ have variations of less than 10% and 6℃, respectively, indicating that the Al-Cu-Si alloys have good thermal stability after high temperature oxidation.