Tensile Strength Of Alloy Research Articles

Effects of rare earth modification on microstructure refinement and mechanical properties of Al-2 wt%Fe alloys

The microstructure and mechanical properties of Al-2 wt%Fe alloys after mixed RE modification, homogeneous annealing and cold rolling have been studied using OM, XRD, SEM and mechanical testing. Results showed that during traditional casting, the α-Al grain and Al3Fe/Al6Fe intermetallic could be effectively refined by the mixed RE in Al-2 wt%Fe alloy. The average grain size of primary α-Al with 0.5 wt% RE addition is half smaller than that without RE. The addition of mixed RE makes the mechanical properties of alloys initially increased and then decreased. The RE elements that enriched in front of the solid/liquid interface formed Al8Fe2Ce at grain boundaries of α-Al. An addition of 0.7 wt% mixed RE lead to the preferential formation of the granular Al11Ce3, which the La were dissolved in. However, the formation of Al11Ce3 weakened the refining effect of mixed RE on the microstructure, also deteriorated the mechanical properties of the alloy. Homogeneous annealing decomposes lamellar Al-Fe phase into short rods, and cold rolling process makes the second phase dispersively and uniformly distributed in the primary α-Al matrix. The elongation and tensile strength of alloy with 0.5 wt% mixed RE addition are increased by 50.14% and 10.67% respectively compared with those of unmodified alloy in cold rolled state.

Mechanism of interaction between the Cu/Cr interface and its chemical mixing on tensile strength and electrical conductivity of a Cu-Cr-Zr alloy

Deformed CuCr alloys have high strength and high electrical conductivity and are used in highly-pulsed magnetic field coils, power vacuum fuses, and so on. In this paper, Cu-Cr-Zr alloy ingots were prepared by medium-frequency induction smelting. They then underwent a heat treatment, forging, cold drawing, and intermediate annealing to obtain a fiber material with a diameter of 0.8 mm. The Cu/Cr interface, precipitated phase, and Cu/Cr chemical mutual solution zone were observed by transmission electron microscopy. The mechanism by which the Cu/Cr interface affected the Cu-Cr-Zr alloy tensile strength was analyzed. The influence of chemical mixing of the Cu/Cr interface on the conductivity of the Cu-Cr-Zr alloy was also studied. The results showed that the Cu/Cr semi-coherent interface inhibited the formation of dislocations during large deformation, which gave the Cu-Cr-Zr alloy its high strength. Elimination of chemical mixing at the Cu/Cr interface allowed the conductivity of the Cu-Cr-Zr alloy to remain unchanged after extremely large deformation.

Comparison of ultrasonically enhanced pulsating water jet erosion efficiency on mechanical surface treatment on the surface of aluminum alloy and stainless steel

Presented article is focused on the comparison of erosion efficiency on the surface treatment of ultrasonically enhanced PWJ (pulsating water jet) on different metal materials surfaces. Surfaces of EN X5CrNi18-10 stainless steel and EN-AW 6060 aluminum alloy were evaluated. Pulsating water jet technological factors were set to the following values: pressure was 70 MPa, circular nozzle diameter was 1.19 mm, traverse speed of cutting head was 100 mm s−1 (which is 200 impact for millimeter) for stainless steel and 660 mm s−1 (which is 30 impact per millimeter) for aluminum alloy. The evaluation was made based on the surface topography evaluation, evaluation of microstructure, and microhardness in the transverse cut. The results of the stainless steel surface evaluation show slight erosion of material, with creating microscopic craters. Subsurface deformation was found to a depth of a maximum of 200 μm. Hardness measurement shows 11% higher value of hardness under the affected area compared with a measurement in the center of the sample. From the findings, subsurface deformation strengthening of stainless steel with minimal influence of material surface can be assumed. Surface deformation of aluminum alloy is characterized by the formation of more pronounced depressions and less pronounced protrusions. Depressions were created by a combination of compression and tearing off material parts. A decrease in hardness value of 18% compared with a measurement in the center of the sample. In places of the first indent just below the disintegrated area (up to 600 μm deep), it is possible to assume the material plastic deformation, but the value of aluminum alloy tensile strength Rm is not exceeded. The experimental results from an aluminum alloy evaluation do not confirm the subsurface mechanical strengthening of the material.

Machining response in turning stir cast alumininum alloy based metal matrix composite

Abstract The aim involved in designing metal matrix composite materials is to combine the desirable attributes of metals and Ceramics. Present work is focused on the study of behavior of Aluminum Alloy (LM6) with Aluminium Oxide, Silicon Carbide and Graphite powder composites produced by the stir casting technique. Different % age of reinforcement is used. Tensile test, Hardness Test, performed on the samples obtained by the stir casting process. Spectroscopy was performed to know the presence of the phases of reinforced material. Hardness tester is employed to evaluate the interfacial bonding between the particles and the matrix by indenting the hardness with the Vickers Hardness testing machine. Tensile test was performed to check the comparison between the simple and composite alloy tensile strength. Microstructure test was performed to analysis the structure of material under magnification. Spectroscopy test is performed to scanning the material for different percentage doping of different metals in alloy. The machining was done on lathe machine to test the effect of machining parameters such as cutting speed, feed and depth of cut on MRR of the composite material.

Microstructure evolution and thermal stability of Cu -15Cr in -situ composites

The Cu-15Cr in-situ fiber-reinforced composites sheets were prepared by cold drawing combined with cold rolling process. The evolution process of Cr fibers was studied, and when cold rolling reduction e = 95%, the morphology of Cr fiber at different annealing temperature and the thermal stability of Cu-15Cr alloy were studied. Microstructure was also studied by scanning electron microscopy (SEM). Meanwhile, the tensile strength of the alloy was tested by means of a precision universal tester, and the resistance value of the alloy was determined by using a digital micro-Euclidean instrument. The experimental results show that, with the increase of deformation, Cr dendrites evolve into homogeneous and parallelly arranged Cr fibers, and the cross-section of Cr fibers undergoes a "V" shape transition to "一" shape. In addition, spheroidization of the Cr fibers occurs on edges and extends to the center as annealing temperature rises. Moreover, the Cr fibers remains stable when the annealing temperature is below 550 °C. Furthermore, the tensile strength of Cu-15Cr alloy decreases gradually as the annealing temperature increases, while the electrical conductivity maximizes when annealing at 550 °C. Our study also shows that Cu-15Cr alloy has obtained a better comprehensive performance with tensile strength of 656 MPa and electrical conductivity of 82%IACS after annealing at 450 °C.

Fabrication of Cu-Sn/SiC Metal Matrix Composites and Investigation of its Mechanical and Dry Sliding Wear Properties

Requisite for advanced materials with high hardness, high tensile strength and improved wear properties has been drastically increased in recent times. The main objective of this paper is to fabricate unreinforced copper alloy and Cu-Sn/SiC composite with varying wt% of SiC (5, 10, and 15) by liquid metallurgy route and to investigate its microstructure, mechanical properties and dry sliding wear behavior. The hardness and tensile strength of alloy and composites are measured on Vickers micro hardness tester and Universal Testing Machine respectively. Tensile test specimens are further subjected to fractography analysis and the results shows ductile mode of failure for alloy and mixed ductile and brittle mode failure for composites. Based on the test results, it is observed that Cu-Sn/10 wt% of SiC have uniform distribution of particles with optimum mechanical properties. Hence only these 10 wt% SiC composite is considered for dry sliding wear analysis and experiments are conducted using Pin-on-disc tribometer. Analysis of process parameters in three levels such as applied load (15,25,35 N), sliding distance (750,1250,1750 m) and sliding velocity (1,2 and 3 m/s) is done by Taguchi’s Design of Experiments technique based on L₂₇ orthogonal array. From Signal-to-Noise ratio and Analysis of Variance approach, the rank of process parameters as well as its influence on the response is found. The results reveal that the wear rate increases as applied load and sliding distance increases and the wear rate decreases as sliding velocity increases. The load is found to have the highest influence on wear rate (38.5%) followed by sliding distance (7%) and sliding velocity (7%). Interaction between the process parameters also contributed towards wear rate. The worn surfaces were examined using Scanning Electron Microscopy and observed the formation of mechanically mixed layer at high velocity condition. Thus, the fabricated composites can be used in applications like bearings and bushes to improve the wear resistance.

Effect of Sc on As-Cast Microstructures and Mechanical Properties of Al-Si-Mg-Cu-Ti Alloys

The as-cast microstructures and mechanical properties of Al-Si-Mg-Cu-Ti alloys with and without Sc were investigated by metallographic microscope, field emission scanning electron microscope, energy spectrum analysis, transmission electron microscope and universal testing machine. The result shows that adding 0.20wt.% Sc into the casting alloy can refine the grain, change the growth morphology from dendrite to fine equiaxed grain, and the morphology of eutectic Si by rough laminar structure into fine fibrous. The tensile strength of alloy with 0.20wt.% Sc is up to 304.4 MPa after T6 heat treated, which is close to that of 6061 forging aluminum alloy.

Mg ve Ti ilaveli Al Alaşımlarının Çekme Mukavemetinin Optimizasyonu

In this study, the influences of magnesium and titanium elements on the ultimate tensile strength of aluminum alloys were analyzed. The alloys were produced with sand casting method. Magnesium and titanium contents in the alloys were varied from 2 to 14 wt.% and from 1 to 3 wt.%, respectively. Tensile tests were carried out at a tensile speed of 1 mm/min and room temperature. The tensile strength of these alloys was also investigated using the artificial neural network approach. Linear correlations of train and test results were observed to be 99.12 and 91.88%, respectively. It was seen that magnesium has a greater effect than aluminum and titanium on the tensile behavior.

Effect of Metallurgical Parameters on the Performance of Al-2%Cu-Based Alloys

The present study was performed on a recently developed Al–Cu alloy, designed for automotive applications. This alloy has the composition Al-2%Cu-1.32%Si-0.42%Mg-0.58%Fe-0.59%Mn-0.07%Ti. It was determined that the alloy containing (0.5% Zr + 0.15% Ti) was the most effective in maximizing the alloy tensile strength over the range of aging temperatures studied, from 155 to 300 °C. The addition of Ag is beneficial at high aging temperatures, in the range of 240–300 °C when added simultaneously with 0.27 wt% Zr. However, it is less effective when compared to a high Zr concentration (about 0.62 wt%) at the same levels of Ti. It is concluded that the alloy tensile properties may be determined by contributions from different strengthening mechanisms, namely the grain size, the volume fraction of intermetallics produced, and evolution and growth of the hardening precipitates with respect to the aging conditions. Quality charts constructed from the tensile data may be used to select the appropriate metallurgical conditions for tailoring the alloy properties to those required for a specific application. Increasing the copper content from 2 to 3.5 wt% does not produce a significant increase in the alloy strength. However, it increases the calculated alloy density from approximately 2.78 to 2.93 g/cm3.

Improvement of damping properties in laser processed superelastic Cu-Al-Mn shape memory alloys

Cu-based shape memory alloys may be a prime candidate to replace NiTi in specific applications due to their reduced cost and excellent superelasticity. Superelastic Cu-Al-Mn alloy is currently being studied for potential applications as damping systems in seismic devices. However, joining techniques are often required to obtain complex shapes to be incorporated into multi-functional systems. In this study, the effect of post-weld laser processing was investigated in a laser welded superelastic Cu-17Al-11.4Mn (at.%) alloy and the mechanical properties were assessed. It was observed that post-weld laser processing increased the alloy tensile strength to almost the double of the as-welded material while the capability to absorb energy during mechanical cycling increased up to 1.7 times. Thus, laser processing was seen as a suitable technique to improve mechanical properties of welded CuAlMn alloys, supporting the use of these materials in applications where both strength and energy absorption are required, such as in seismic applications.

Study on microstructure evolution of deformed Mg-Gd-Y-Nd-Zr heat-resistant magnesium alloys after solid solution and ageing

The microstructure evolution of Mg-Gd-Y-Nd-Zr heat-resistant magnesium alloy after deformation and T5 or T6 treatment were studied. In thermoplastic deformation, dynamic recrystallization and dynamic precipitation has been taken place at the same time. The dynamic precipitation reduces the recrystallization nucleation driving force in the grain; it will prevent to occur dynamic recrystallization partially. Solid solution temperature was 530oC and hold 4h. Age hardening treatments were performed at 225oC and hold 16h. The alloy showed the comprehensive properties are obviously improved from T6 to T5 heat treatment. After T5 heat treatment the tensile strength of alloy increased to 359.3 MPa, increased by around 48.5%; Elongation is increasing from 5.17% to 6.5%. After peak ageing treatment, the main precipitation is ?' phase, the precipitation phase have obvious pinning effect to grain boundary of the alloy, it will prevent the grain growth ageing for a long-time. At the same time, strengthening role of precipitate phase make its strength increased significantly.

Effect of Different Operating Temperatures on Mechanical Properties of Several Rolled Aluminum Alloys

The five kinds of 1100, 1050, 1108, 8079 and 8079H alloy sheets have been prepared by melting, casting and rolling process and tensile strength and elongation of alloys have been tested at room temperature, 100°C, 200°C, 300 °C. For provide a reference of the mechanical properties for the applications of these alloys. It was indicated that the mechanical properties of alloys were significantly different at different operating temperatures, the overall trend is that the tensile strength (σb) of the alloys decreased significantly and the breaking elongation (εb) of the alloys remarkably increased with the increase of the testing temperatures. The tensile strength of the alloys are about 30MPa at 300°C, so the operating temperature of the alloys should be controlled below 300°C.

Influence of thermal treatment on microstructure, mechanical and degradation properties of Zn–3Mg alloy as potential biodegradable implant material

Abstract In this study, the influence of homogenisation heat treatment effect on Zn–3Mg alloy proposed for biodegradable bone implants was investigated. The alloy was developed via casting process from high purity raw materials and homogenised at 360 °C for 15 h followed by water quenching. Results revealed that the microstructure of as cast alloy was composed of dendritic structure of Zn-rich phase distributed in segregated pattern within Mg 2 Zn 11 eutectic phase. Exposure to the long duration heating of homogenisation apparently broke the dendrites and transformed them into connected precipitates within the alloy's matrix. Non-equilibrium thermal analysis revealed the formation of Mg 2 Zn 11 eutectic phase which nucleated at 367 °C and solidified completely at 354 °C. The eutectic coherency point occurred at 368 °C and 424 s when 30% of solid has precipitated during solidification. Homogenisation resulted into lowering the alloy's tensile strength from 104 MPa to 88 MPa but improving elongation at fracture from 2.3% to 8.8%. The homogenised Zn–3Mg alloy showed improved corrosion resistance (corrosion rate = 0.13 mmpy) compared to the as-cast one (corrosion rate = 0.21 mmpy). The mechanical property and corrosion behaviour of the homogenised alloy seem suitable for biodegradable implant applications.

Effects of Melt Thermal-Rate Treatment and Modification of Y on Zn-27Al Alloy

In this paper, the effects of melt thermal-rate treatment (MTRT) and modification of Y on the microstructure and mechanical properties of Zn-27Al alloy are discussed. The experimental results suggest that the microstructure can be refined and the mechanical properties can be improved with the MTRT technique. The effect of grain refinement achieves the best when the melt temperature is up to 830°C, the tensile strength of alloy is 452 MPa and the hardness is 123 HB, each measure increasing by 13.6% and 7.1% compared with the untreated alloy, respectively. When the alloy is treated with the MTRT + Y technique, the mechanical properties of the alloys cannot improve compared with that of the alloy treated with MTRT. The mechanism of the effects of MTRT and Y are discussed.

Effects of Y and Y Combined with Al-5Ti-1B on the Microstructure and Mechanical Properties of Hypoeutectic Al-Si Alloy

In this article, the effects of Y and combined additions of Y and Al-5Ti-1B on the microstructure and mechanical properties of hypoeutectic Al-Si alloy were studied. The experimental results showed that the addition of Y in hypoeutectic Al-Si alloy can refine the grain and improve the mechanical properties. The optimal addition amount of Y is 0.2 wt.%. Under this addition amount, the effect of grain refinement achieved the best, the tensile strength of alloy is 228 MPa, the yield strength is 136 MPa, elongation is 3.18%, hardness is 85 HB. Each measure increased by 12.8%, 17.2%, 31.9%, and 9.6%, respectively, compared with that of the unmodified alloy. Y and Al-5Ti-1B combined treatment had a certain degree of refinement for a-Al phase, but the size of eutectic silicon increased and massive structure appeared. Compared with the alloy modified with 0.2 wt.% Y, the mechanical properties decreased. The mechanism of effect of Y and Al-5Ti-1B was discussed.

Effect of Element V on the Microstructure and Mechanical Properties of DZ417G Superalloy

The effect of V content on the mechanical properties and microstructure of DZ417G alloy was studied in the present investigation. DZ417G alloy with different element V contents was smelted , then tested the mechanical properties and observed microstructure. The results show that with the increase of element V content, the morphology of rod type M23C6 carbides turned into block-type MC carbides, the size of carbides became bigger, and the amount of carbides decrased, but the dispersion degree of carbide in the matrix was increased. The alloy tensile strength and plastic properties were increased at high temperature with the increment of V content. There were finer dimple structures on the tensile rupture fracture surface of the alloy with high element V than the alloy with low element V under the high temperature conditions. The results of creep rupture life tests show that with increasing V content the creep rupture life increased at the test condition of 760 °C, 725MPa. The creep rupture life is 90h of the alloy with 0.62% V element content, and the creep rupture life increased to more than 245h when the element V content increased to 0.96%.

Effects of Si addition on properties of Fe–Cr–W–Ti–Y2O3 alloy fabricated by mechanical alloying

Effects of Si element on characteristics of Fe–Cr–W–Ti–Y2O3 alloy, including relative density, tensile strength, oxidation resistance and microstructure had been investigated. The results showed that the alloy with Si addition appeared superior properties than alloy without Si. The relative density and tensile strength of alloy without Si were only around 85% and 300MPa, while that of alloy adding Si could reach up to 96.8% and 692.7MPa after sintering at 1350°C. Mass gain of alloy adding Si was approximately one tenth that of alloy without Si when oxidized at 650°C and 850°C. These superior properties were attributed to action of Si in sintering and oxidation processes. It would activate the sintering for more dense alloy, and form protective oxidized film preventing diffusion of oxygen and metal atoms.

Effect of Aging Treatments on Microstructure and Exfoliation Corrosion Behavior of Spray Forming 7075 Alloy

Mechanical properties, microstructure and exfoliation corrosion (EXCO) behavior of spraying forming 7075 alloy underwent retrogression and re-aging (RRA) were studied by tensile test, transmission electron microscopy and EXCO test, and compared with those of T6 peak aging and T73 overaging treatments. The results show that after T6 treatment, abundance transgranular dispersive η phases make tensile strength of the alloy reach 760MPa, elongation and EXCO rating are only 4.8% and ED respectively by dint of continuous η phases at grain boundaries and narrow precipitate free zones (PFZ). After T73 treatment, interrupted η phases at grain boundaries and wide PFZ can improve elongation and EXCO resistance, but depressed volume fraction of coarsening transgranular η phases reduce tensile strength to 676MPa. After RRA treatment (120°C/24h + 200°C/10min + 120°C/24h), abundance transgranular dispersive η phases separate out again, η phases at grain boundaries interrupt, and PFZ widen slightly. Tensile strength, elongation and EXCO rating of alloy are 758MPa, 8.4% and EA respectively.

Effects of Y, Gd on Microstructure and Mechanical Properties of AZ61 Magnesium Alloy

The effects of Y and Gd on the microstructure and mechanical properties of AZ81 magnesium alloy were studied by alloy preparation, microstructure analysis and mechanical property testing. The results show that moderate addition of Y and Gd to AZ61 magnesium alloy can obviously refine grains of AZ61 alloy, and decrease the amount of Mg17Al12phase. With the increase of alloying elements, the tensile strength and elongation of aged AZ61 magnesium alloy at the temperature ranging of 25°C～175°C rise at first and then drop.When content of Y and Gd is up to 2.7%，the values of tensile strength of the alloy at room temperature and 175°C are up to their maximums, 254MPa and 164MPa respectively, while the elongation of the alloy are 22.9%,18.7% respectively. Y and Gd improve the mechanical properties of AZ61 alloy because of the grain refining strengthening, solution strengthening and the dispersion strengthening.

First-principle study of interfacial properties of Ni–Ni3Si composite

In order to explore the interfacial structure of Ni/Ni3Si (001) interfaces and clarify the heterogeneous nucleation potential of α-Ni grains on Ni3Si particles in Ni–Ni3Si eutectic alloys, the work of adhesion, electronic structure, and interface energy have been studied by first-principle method based on density functional theory (DFT). Surface convergence tests show that Ni3Si (001) slabs with more than eight layers exhibit bulk-like interior feature. The values of adhesion work and interfacial distance suggest the Ni+Si-terminated interface with hollow site stacking is the most thermodynamic stable and has the largest critical stress for crack propagation among the four models, indicating the precipitates of Ni3Si can improve stability and tensile strength of alloys. This interface has covalent feature, which is mainly contributed by the hybridization of Ni-3d and Si-3p orbital electron. The calculated interface energy of Ni/Ni3Si (001) interface is smaller than that between the α-Ni and nickel melts, elucidating the excellent nucleation potency of Ni3Si particles for α-Ni grains from thermodynamic considerations.