Effect Of Solution Treatment Research Articles

Effects of Open Atmosphere Solutionizing Treatment on the Microstructural and Mechanical Properties of Porous 60NiTi Parts

Titanium alloys have been widely used for medical implants due to their good biocompatibility and excellent corrosion resistance. 60NiTi, an intermetallic nickel-titanium alloy containing approximately 60 wt.% Ni and 40 wt.% Ti, is a promising material for medical components such as implants and prostheses. 60NiTi is hard with good biocompatibility, highly corrosion resistant and has relatively low stiffness. In this study, conventional press-and -sinter method was employed to produce porous 60NiTi parts suitable for general bone replacement applications such as spinal and cranial inserts. The effect of solution treatment in a non-protected furnace and water quenching on the mechanical and microstructural properties of 60NiTi were investigated. It was found that this procedure produces a hard integral ceramic layer, a complex mixture of nickel and titanium oxide compounds, on the surface and around the pores of 60NiTi parts. Results showed that this heat treatment procedure causes the embrittlement of the parts due to an increase in oxide content. However, the produced ceramic surface can also enhance the resistance to corrosion, which is beneficial from a biocompatibility point of view.

Effect of solution treatment on deep drawability of IN718 sheets: Experimental analysis and metallurgical characterization

A promising approach to decrease deformation load and improve ductility during forming of Inconel-718 (IN718) is through the use of solution treated blanks. In the present work, IN718 sheets were separately solution treated to different temperatures in the domain of 970–1070°C at an interval of 50°C to dissolve the strengthening precipitates (γ′ and γ′′), and subsequently, were oil quenched to retain the microstructure. Due to significant difference in average grain size, the solution treated samples of 970°C (HT970) and 1070°C (HT1070) were selected for tensile characterization, deep drawing analysis, and micro-texture evolution. The tensile test response showed approximately 30% improvement in ductility and 27% reduction in load in case of HT1070 material with respect to that of HT970 material. The deep drawing process window was evaluated using flat bottom and hemispherical dome punch geometries, and it was found that the limiting draw ratio (LDR) improved marginally by 4.5% in case of HT1070 material. This improvement was due to the dominating presence of cube component in initial texture of HT1070 material. The high presence of cube and goss components in initial texture and the large difference in Taylor factor of individual grains at critical regions of deep drawn cups led to higher unsatisfactory surface roughness in the case of HT1070 material. Hence, it is suggested that the deep drawn components of HT970 material has better part performance in terms of surface roughness. Further, an attempt was made to correlate the fractographs with the fracture and formability behavior of sheet metal.

Effects of solution treatment on microstructures and micro-hardness of a Sr-modified Al-Si-Mg alloy

The microstructures and micro-hardness of a solution-treated Sr-modified Al-Si-Mg alloy are investigated. The dimension and shape factor of eutectic Si particles, as well as the mean diameter and fraction of Si-containing dispersoids, are quantitatively measured. It is revealed that the best spheroidized and refined eutectic Si particles can be obtained when the solution time is about 2 h. With further raising the solution time, the eutectic Si particle grows up anisotropically and exhibits facet characteristics with sharp edges. Meanwhile, some coarsened particles appear by mutual overlapping. Moreover, the Si-rich phases in α-Al matrix facilitate the precipitation of Si-containing dispersoids. The enhanced precipitation of Si-containing dispersoids with raising solution time leads to the formation of dispersoids free zones (DFZs) between two adjoint Si-containing dispersoids regions or in the areas adjacent to eutectics. Additionally, the solution strengthening effect of Mg atoms is stronger than that of Si atoms, which contributes to the increased micro-hardness of α-Al matrix in the initial solution stage. The dispersion strengthening effect of Si-containing dispersoids first increases then remains almost unchanged, revealing the change rule of micro-hardness in α-Al matrix during the later solution treatment. Furthermore, the lower micro-hardness of (Al+Si) eutectics is strongly related with the smaller eutectic Si particles.

Effect of Solution Treatment on Microstructure and Mechanical Properties of A356.2 Aluminum Alloy Treated With Al–Sr–La Master Alloy

Morphology and mechanical performances of A356.2 aluminum alloy under solution treatment are important for its application, specifically for alloys treated with newly‐developed combined refiner‐modifier. In this work, effect of solution temperature, solution time, and quenching medium temperature on the microstructure and mechanical properties of A356.2 aluminum alloy treated with Al–6Sr–7La master alloy are investigated. Results show that eutectic silicon undergo disintegration, spheroidization, and coarsening stages with solution temperature increasing. Volume fraction of eutectic silicon decreases gradually with solution temperature increasing from 495 to 550 °C, while secondary dendritic arm spacing (SDAS) increases gradually during this process. At the solution temperature of 540 °C, aspect ratio of eutectic silicon approached to about 1.3 and eutectic silicon undergo spheroidization and coarsening stages with extension of solution time. Moreover, SDAS increases with increasing of quenching medium temperature, which affects the ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) of the alloy, especially for tensile strength and elongation. Optimal solution parameters for A356.2 aluminum alloy treated with Al–6Sr–7La are obtained and the reasons are discussed.

Effect of Solution Treatment on Microstructure and Corrosion Properties of Mg–4Gd–1Y–1Zn–0.5Ca–1Zr Alloy

The as-cast multi-element Mg–4Gd–1Y–1Zn–0.5Ca–1Zr alloy with low rare earth additions was prepared, and the solution treatment was applied at different temperatures. The microstructural evolution of the alloy was characterized by optical microscopy and scanning electron microscopy, and corrosion properties of the alloy in 3.5% NaCl solution were evaluated by immersion and electrochemical tests. The results indicate that the as-cast alloy is composed of the α-Mg matrix, lamellar long-period stacking-ordered (LPSO) structure and eutectic phase. The LPSO structure exists with more volume fraction in the alloy solution-treated at 440 °C, but disappears with the increase in the solution temperature. For all the solution-treated alloys, the precipitated phases are detected. The corrosion rates of the alloys decrease first and then increase slightly with the increase in the solution temperature, and the corrosion resistance of the solution-treated alloys is more than four times as good as that of the as-cast alloy. In addition, the alloy solution-treated at 480 °C for 6 h shows the best corrosion property.

Effects of solution treatment on mechanical properties and corrosion resistance of 4A duplex stainless steel

Abstract In this study, 4A duplex stainless steels were prepared via remelting in an intermediate frequency furnace and subsequently solution treated at different temperatures. The effects of solution treatment on the mechanical properties and corrosion resistance of 4A duplex stainless steel were investigated. Microstructures were characterized via optical microscopy and scanning electron microscopy. The mechanical properties were evaluated via hardness test, tensile test, and impact test experiments. The point corrosion resistance was studied via chemical immersion and potentiodynamic anodic polarization. The results showed that with increasing solution temperature in the range of 1 223 – 1 423 K, the tensile strength and hardness first decreased and then increased, and minimum values were obtained at 1 323 K. The σ phase precipitated at the boundaries of the α/γ phases in samples solution treated at 1 223 K, decreasing both impact energy and pitting potential of the experimental steels. When experimental steels were solution treated at 1 373 K for 2 h, a suitable volume fraction of α/γ was uniformly distributed throughout the microstructure, and the steels exhibited optimal mechanical properties and pitting corrosion resistance.

Effect of Solution Treatment on Microstructure and Properties of Gd - AZ91 Magnesium Alloy

In this paper, the Gd-AZ91 alloy was manufactured by adding rare earth element Gd in AZ91 magnesium alloy. The effects of solution treatment on the microstructures of rare earth elements Gd were investigated by means of optical microscopy, scanning electron microscopy, X-ray diffraction analysis and equipment for testing mechanical properties. The experimental results show that the addition of rare earth element Gd in AZ91 magnesium alloy can refine the alloy grain, turn β-Mg17Al12 phase into a discontinuous network or point structure, and produce granular compound Al2Gd in the alloy; when solution temperature is about 380 °C, the alloy structure is the best, the tensile strength of the alloy is the largest with the value larger than 250Mpa; when the solution temperature exceeds 380 °C, the alloy structure is coarsened and the mechanical properties of the alloy are reduced. With the increase of rare earth element Gd content, the tensile strength of the alloy shows a tendency to increase gradually, which Indicates that the addition of a certain amount of rare earth elements Gd can improve the plasticity of the alloy.

Effects of solution treatment on microstructure and superelasticity of FeNiCoAlTaB alloy

The effects of solution treatment on the microstructure, macrotexture and superelastic properties of FeNiCoAlTaB alloy were investigated in this study. The results showed that rolling texture of (011) [2-11] (Brass-type) developed by cold-rolling with reduction of 98.5% transferred to (023) [100] and (032) [100] texture after solution treatment with the temperature above 1200 °C, forming a strong 〈100〉 fiber recrystallization texture. Solution treatments at the temperature above 1250 °C facilitated the formation of a single austenite phase which was in favor of the precipitation of γ′ phase during aging treatment and martensitic transformation in cyclic tension. In addition, microcracks appeared readily in the alloy for solution treatment with the temperature above 1300 °C, which negatively affected the superelastic performance. Under the experimental conditions of this study, the 98.5% cold-rolled FeNiCoAlTaB alloy acquired a preferable superelasticity after solution treatment at 1250 °C for 1 h and aging treatment at 600 °C for 72 h, with the total tensile strain of 3.8%, the complete cyclic superelastic strain of 1.6% and the tensile strength of 885 MPa.

Effect of solution treatment and precipitation aging conditions on microstructural refurbishment in cast nickel base superalloy, grade MGA 1400

The aim of this project is to study and evaluate the effect of reheat treatment conditions on microstructural refurbishment in cast nickel base superalloy, MGA 1400. This cast nickel base superalloy is used as a turbine blade material in Japanese gas turbine engines. The evaluated reheat treatment process consists of a solution treatment at 1125°C, 1150°C and 1175°C for 4 hours and followed by 1) final precipitation aging at 845°C for 25 hours or 2) primary aging at 925°C for 2 hours and secondary aging at 845°C for 25 hours. All reheat treated microstructures were investigated and analyzed by SEM and image analysis program. From all obtained results, it was found that at temperature of 1125°C for 4 hours followed by single precipitation aging at 845°C for 25 hours (without 2-steps aging) provides the best microstructural characteristics, which consists of the most uniform distribution of very dense gamma prime particles precipitating with its proper size and shape in the gamma matrix.

Effect of solution treatment on the microstructure, tensile properties, and corrosion behavior of the Mg–5Sn–2Zn–0.1Mn alloy

Working on magnesium alloys containing relatively inexpensive alloying elements such as tin, zinc, and manganese have been a target for many studies. The binary Mg–Sn and Mg–Zn systems have a wide range of solid solubility which make them heat-treatable alloys. In the present study, the microstructure, tensile properties, and corrosion behavior of the Mg–5Sn–2Zn–0.1Mn alloy was studied in the as cast state and after heat treatment at a temperature reaching 450 °C for about 24 h. It was found that a noticeable enhancement in strength and corrosion resistance was achieved through heat treatment. The strength of the as cast alloy increased from 76.24 ± 6.21 MPa to 187.33 ± 10.3 MPa, while the corrosion rate decreased from 1.129 to 0.399 mm y−1.

Effect of Solution Treatment on Age-Hardening Behavior of Al-12Si-1Mg-1Cu Piston Alloy with Trace-Zr Addition

800x600 Normal 0 21 false false false PL X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Standardowy; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Calibri,sans-serif; mso-bidi-font-family:Times New Roman;} The influence of a solution treatment with a trace zirconium addition on the precipitation behavior of a cast Al-12%Si-1%Mg-1%Cu piston alloy has been reported. The alloys were prepared by controlled melting and casting. The cast alloys were given an age-hardening treatment having a sequence of homogenization , T6 solutionizing, quenching, and aging. Both the cast and solutionized samples were naturally aged for 58 days, isochronally aged for 60 minutes at different temperatures (up to 350°C), and isothermally aged at various temperatures (up to 225°C) for different periods of time (ranging from 15 to 360 minutes). The hardness values of the differently processed alloys were measured to understand the aging behavior of the alloys. Electrical resistivity changes with aging time and temperature were measured to understand the precipitation behavior of the alloys. It is observed that significant hardening takes place in the aged alloys due to the formation of GP zones as well as the formation of metastable phases. The solutionizing treatment improves the hardness because some alloying elements are re-dissolved during solution treatment to produce a solute-rich solid solution. The trace-added Zr hinders the softening due to the precipitation of Al 3 Zr, which is very stable against coarsening and the re-dissolution of precipitates. Electrical resistivity decreases due to stress relieving, the dissolution of the metastable phase, and precipitation coarsening. The resistivity of the solutionized alloys decreases more due to the higher concentration of elements in the solid solution. A microstructural study of the alloys reveals that the solution treatment improves the distribution of the silicon grains. It is also observed that the alloys attained an almost fully re-crystallized state after aging at 350°C for 90 minutes.

Selection of optimal solution heat treatment of the casting cylinder heads

The effect of solution treatment on mechanical properties (UTS, elongation, Brinell hardness) and microstructure (Si-morphology and Si-size) of an aluminium alloy (A356) used for casting cylinder heads was studied. The tests were carried out with specimens machined from the bulkheads of V8 engine blocks cast by the low pressure process. The samples were tested in as-cast and T6 heat treating conditions (solution heat treatment at 530°C with different time - 2, 3, 4, 5, 6, 7 hours, quenching in water at 20°C and precipitation hardened for 4 hour at 160°C). The results show that used heat treatment improves mechanical properties of the cylinder head casts. Tensile strength and hardness of specimens increase with solution treatment time. The hardness is a reflection of solution strengthening and silicon particle distribution in matrix. Solution temperature 530°C and 5 hours solution time is appropriate to obtain better morphology and distribution of Si particles in microstructure. Prolonged solution treatment (more than 5 hours) leads to a coarsening of the Si particles, while the numerical Si density decreases. As the particle density decreases, a fewer number of sites are available for crack nucleation, and hence, the fracture properties are improved. The data obtained from this study will be used to improve process control, and to help the selection of heat treatment of the casting for future products.

Microstructure and mechanical properties of 7A56 aluminum alloy after solution treatment

The effect of solution treatment on the microstructure and mechanical properties of a novel 7A56 aluminum alloy plate was investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), conductivity, hardness and tensile tests. The results indicate that the coarse second phases in the hot-rolled plate mainly consist of AlZnMgCu quaternary phase and Al7Cu2Fe phase, and no Al2CuMg phase is found. The amount of the second phases gradually reduces with the increase in temperature (450–480 °C) and time (1–8 h) during the solution treatment, and the soluble particles are completely dissolved into the matrix after solution treatment at 470 °C for 4 h, while the residual phases are mainly Fe-rich phase along the grain boundaries. The recrystallization fraction of the alloy gradually increases with the degree of solution treatment deepened. When the temperature exceeds 480 °C, over-burning takes place. The mechanical properties of samples treated at 470 °C for various times were tested. After the solution treated at 470 °C for 4 h, the quenching conductivity and peak-aged hardness of the alloy are 30.8%IACS and HV 204, respectively. The ultimate tensile strength and yield strength of the samples aged at 120 °C for 24 h are 661 and 588 MPa, respectively.

Effect of Solution Treatment on Precipitation Behaviors, Age Hardening Response and Creep Properties of Elektron21 Alloy Reinforced by AlN Nanoparticles.

In the present study, the solution and ageing treatments behavior of Mg-RE-Zr-Zn alloy (Elektron21) and its nano-AlN reinforced nanocomposites have been evaluated. The properties of the thermal-treated materials were investigated in terms of Vickers hardness, the area fraction of precipitates, microstructure and phase composition. The solution treatments were performed by treating at 520 °C, 550 °C and 580 °C in argon atmosphere. The outcomes show that the hardness of the solutionized alloys was slightly affected by the solution temperature. X-ray diffraction and image analysis revealed that the complete dissolution of precipitates was not possible, neither for Elektron21 (El21) nor for its AlN containing nanocomposites. The ageing treatment of El21 led to a significant improvement in hardness after 20 h, while for longer times, it progressively decreased. The effect of ageing on the hardness of El21–AlN composites was found to be much less than this effect on the hardness of the host alloy. Electron backscatter diffraction (EBSD) analysis of El21 and El21–1%AlN after solution treatment confirm the random orientation of grains with a typical texture of random distribution. The as-cast creep results showed that the incorporation of nanoparticles could effectively improve the creep properties, while the results after solution treatment at 520 °C for 12 h followed by ageing treatment at 200 °C for 20 h confirmed that the minimum creep rate of T6-El21 was almost equal to the as-cast El21–AlN.

Effect of solution treatment on mechanical and corrosion resistance properties of Mg–Zn–Nd–xCa alloy

The effect of solution treatment on compression mechanical and corrosion resistance properties of Mg–6Zn–0.5Nd–xCa alloys has been investigated in the current study. The results show that with solution treatment, the corrosion rate of Mg–6Zn–0.5Nd–xCa alloy was reduced to 1.51 mm yr−1. The corrosion mechanism of Mg–6Zn–0.5Nd–xCa alloys tend to be uniform corrosion because of the secondary phase particle is diffused into matrix. The fracture strength of Mg–6Zn–0.5Nd–0.3Ca alloy has been dramatically increased by about 68%. With Ca content increasing, grains are refined and the compression mechanical properties of cast alloys are gradually increased to some extent. The Mg–6Zn–0.5Nd–0.5Ca alloy shows great corrosion resistance than other studied alloys.

Evolution of microstructures and mechanical properties during solution treatment of a Ti–V–Mo-containing high‑manganese cryogenic steel

The effect of solution treatment on the microstructure and mechanical properties of a high‑manganese (Mn) twin-induced plastic (TWIP) cryogenic steel that was alloyed from elemental titanium (Ti), vanadium (V) and molybdenum (Mo) was investigated by a variety of techniques such as microstructural characterization, room tensile testing and −196°C impact testing. The austenite grain size grew slowly with an increase of the solutionizing temperature (ST). The relatively weak effect of the ST on the austenite grain size is attributed to the superior thermal stability and coarsening resistance of the (Ti, V, Mo)C precipitate, which hindered austenite grain growth. An increase in ST improved the low-temperature toughness (LTT) significantly and decreased the strain hardening rate (SHR), but had no significant effect on the yield strength. The Hall–Petch strengthening coefficient for yield strength was small, and was estimated to be 153MPaμm0.5. Undissolved large-sized chromium (Cr) carbide can deteriorate the LTT significantly. Because of its excellent mechanical properties, high-Mn steel that was alloyed by elemental Ti, V and Mo can be used to manufacture storage tanks for liquefied natural gas.

Effect of solution treatment on microstructure and cryogenic toughness of 316LN austenite stainless steel weld metal welded by NG-MAG arc welding

In this paper, the effect of solution treatment on microstructure, micro-hardness and cryogenic toughness of 316LN weld metal welded by NG-MAG arc welding was investigated by electron microscopy, hardness measurements and charpy V impact tests. After a proper solution treatment, the dendritic sub-grains could disappear, the segregation of Mn and Mo at the sub-grain boundaries could be completely eliminated and the dislocation density drop significantly. All these aspects contributed to the significant improvement of cryogenic toughness. Specifically, the fracture morphology with respect to the solution temperature was discussed. Finally, the maximum fracture toughness at cryogenic temperature was obtained after solution treatment at 1100°C for 2h.

Evolution of second phases and mechanical properties of 7075 Al alloy processed by solution heat treatment

Abstract The effects of solution treatment on the evolution of the second phases and mechanical properties of 7075 Al alloy were studied with scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), hardness and tensile tests. The results show that Mg(Zn, Cu, Al)2 phases gradually dissolve into the matrix, yet the size and morphology of Al7Cu2Fe phase exhibit no change with the increase of the solution treatment temperature and time due to its high melting point. When the solution treatment temperature and time continue to increase, the formation of coarse black Mg2Si particles occurs. Compared to the as-cast alloy, the microhardness, tensile strength, and elongation of the sample under solution heat treatment at 460 °C for 5 h are increased by 55.1%, 40.9% and 109.1%, respectively. This is because the eutectic Mg(Zn, Cu, Al)2 phases almost completely dissolve and basically no coarse black Mg2Si particles are formed.

Achieving high strength and ductility in double-sided friction stir processing 7050-T7451 aluminum alloy

In this paper, a novel approach named double-sided friction stir processing (DFSP) was proposed to prepare 7050-T7451 aluminum alloy plates, and effects of solution treatment (ST) on microstructures and mechanical properties of DFSP were investigated. The solution treatment at 470°C for 4.5h was employed. 7050-T7451 and 7050-ST aluminum alloy plates were used for DFSP, and their experimental results were compared. A significant grain refinement to an average 1.5–2.2µm was attained by DFSP for both 7050-T7451 and 7050-ST plates. The microstructure exhibits a bimodal character which consists of fine grains with the size of 1–6µm and ultrafine grains with the size of ~1µm. The precipitated particles in the SZ of T7451-DFSPed and ST-DFSPed plates are MgZn2 and MgAlCu/Al7Cu2Fe. Compared with the T7451-DFSPed plate, the ST-DFSP one shows a higher dissolution degree of Mg and Zn elements, and most dispersoid are retained as η′ phase, additionally, the homogenization of the microhardness distribution of the ST-DFSP plate is improved and a higher tensile strength is obtained while good ductility is maintained.

Effect of Solution Treatment on the Microstructure and Mechanical Properties of IN718 Alloy

Abstract IN718 alloy exhibits excellent mechanical properties at high-temperature and good workability, which has been widely used in aircraft engine turbine disks, compressor disks, and power turbine shafts (i.e. rotating components). The mechanical properties of IN718 alloy, especially its creep and fatigue properties are a key factor determining the safety and reliability of engines. In this study, the effects of solution treatment at temperature ranging from 900 °C to 1050 °C on the microstructure and mechanical properties (including the tensile strength at room temperature and 650 °C, the stress-rupture behavior at 650 °C and 700 MPa, and the low-cycle fatigue behavior at 450 °C) were investigated by optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results show that in specimens subjected to solution treatment at temperature from 900 °C to 990 °C, the mass fraction of the δ-phase decreases with increasing temperature, whereas the grain size remains the same. However, in specimens treated at temperature ranging from 990 °C to 1050 °C, the δ-phase is dissolved and the grain size increases from 15 μm to 100 μm. With proper adjustment of the microstructure of IN718 alloy, this material can satisfy the requirements for high-temperature, corrosion-resistance, and radiation-tolerance, such as the aviation, petrochemical, and nuclear power industries.