Effect Of Solid-solution Temperature Research Articles

Effects of solid solution and aging treatment on the microstructure evolution of Ti2AlNb alloy

The effects of solid solution temperature, aging temperature and aging cooling rate on the microstructure evolution of forged Ti-22.5Al-24.7Nb (at. %) alloy were investigated. With the increasing solid solution temperature, the number of equiaxed microstructure first increases and then decreases, reaching the maximum at 900 °C. Lamellar microstructure solubilizes in the matrix or gradually becomes coarser and shorter, and transforms into equiaxed microstructure. When the solution temperature is 1000 °C, equiaxed α2 phase gradually changes to be lath-shaped and concave. During the aging process, some α2 phase transforms into O phase, and the aging temperature affects the shape of equiaxed microstructure and the spacing between the needle-like microstructure. With the increasing aging temperature, the number of equiaxed microstructure increases linearly, and the proportion of fine secondary O phase decreases while the thickness increases. The lamellar morphology of O phase can be retained at a faster cooling rate, while a portion of lamellar O phase is converted to the B2 phase after furnace cooling. Through heat treatment, the volume fraction and the size of lamellar O phase could be well controlled.

Carbide precipitation during tempering of hybrid steel 60

The effects of carbide precipitation on mechanical performance of Hybrid Steel 60, known as a novel bearing steel, have not been investigated. In this study, the austenite transformation temperatures of Hybrid Steel 60 during heating were revealed by the thermal expansion curve. The temperature and effective activation energy of the second phase precipitation were determined by the differential scanning calorimetry (DSC) curve. Different solid solution structures after austenitization were detected using various cooling rates. The solubility temperature was determined based on hardness and residual austenite content. The carbides precipitated at the peak temperature were qualitatively identified using XRD. It was discovered that the temperature points Ac1 and Ac3 of the steel were 786 °C and 864 °C, respectively. In addition, the effect of solid solution temperature on quenching hardness is minimal, while the cooling rate has a greater impact on hardness, reaching a peak at 5 °C s−1. The primary carbide phase in Hybrid Steel 60 is the M7C3 and VC. When the temperature ranges from 500 °C to 550 °C, M23C6 begins to precipitate. As a result, after tempering at 525 °C, the hardness peak value reached 566 HV.

Improving the comprehensive mechanical property of the AlSi10Mg alloy via parameter adaptation of selective laser melting and heat treatment

In this work, the AlSi10Mg alloys with distinct molten pool structures, namely fish-scale and lamellar, were fabricated by using selective laser melting (SLM) technology. The effects of solid solution temperature on the microstructural evolution and mechanical properties of the two types of alloys were systematically investigated. The relationship among initial structure, heat treatment and mechanical properties was revealed. The experimental results showed that for the alloy with fish-scale structure, Si diffused more easily after solid solution treatment due to the finer eutectic network, resulting in a larger Si particle size. At 510 °C, the nano Si particles in the fish-scale sample basically disappeared, but a small amount of nano Si particles still existed in the lamellar sample, leading to a bimodal distribution in the Si particle size. Different sizes and distributions of Si particles present different strengthening mechanisms and affect the nucleation and growth of recrystallized grains in the α-Al matrix, leading to significant differences in mechanical properties. The strength of the lamellar sample decreased with increasing the temperature, and the abnormally growth of grains could be found after being treated at 510 °C, resulting in a poor mechanical property. The strength of fish-scale sample first decreased and then increased with the increase of solid solution temperature. When the alloy with fish-scale structure was solid solution treated at 510 °C, Si particles could promote the nucleation of recrystallized grains but hinder their growth, and the ultimate tensile strength decreased from 478.8 MPa of SLMed state to 393.4 MPa, a reduction of 17.8%, while the elongation increased from 7% to 21%, an increase of 300%, showing an excellent overall mechanical property. Therefore, the present study demonstrates that adjusting the SLMed molten pool structure and heat treatment parameters is necessary to obtain a good combination of microstructure and mechanical property.

Effects of heat treatment on microstructure and mechanical properties of squeeze casting AlSi9Mg alloy flywheel housings formed with local supplementary pressure

Targeted squeeze casting components of the thick-walled locations with local supplementary pressure (LSP) can effectively realize the local forced shrinkage, which is very significant for the elimination of shrinkage defects. In this paper, the effects of solid solution temperature, solid solution time, aging temperature and aging time on AlSi9Mg aluminum alloy flywheel housing with large wall thickness difference and complex structure formed with LSP were investigated. The results showed that the LSP effectively refined the microstructure and accelerated the spheroidization process of eutectic silicon, which reduced the heat treatment holding time significantly. The twinning growth of silicon particles effectively hindered the dislocation motion, relieved the stress concentration, and improved the strength. The fishbone-like AlSiMnFe phase were passivated after heat treatment. Heat treatment can enhance the plasticity by breaking and spheroidizing the coarse needle-like eutectic silicon, and enhance the strength by refining and homogenizing the β" phase precipitated in the alloy. The optimum heat treatment parameters are solid solution at 540 °C for 210 min and aging at 175 °C for 480 min. Under the optimum heat treatment condition, the ultimate tensile strength, yield strength and elongation for the position with LSP reached 306.1 MPa, 237.5 MPa, 13.29 %.

Effect of solid solution temperature on microstructure and mechanical properties of Sc-containing 7085 alloy

The microstructure, mechanical properties, and electrical conductivity of 7085 alloy sheet without and with Sc (0.25 wt%) at different solid solution temperatures were investigated by using OM, SEM, TEM, EBSD, XRD, and the strengthening mechanism of the alloys were analyzed. The results show that the micrometer-scale second phases in the 7085 alloy are mainly the T(AlZnMgCu) phase and the Al7Cu2Fe phase, while Al3(Sc, Zr) particle and the AlZnMgCuSc phase are also formed in the 7085-Sc alloy. The Mg, Zn, and Cu elements in the soluble second phase of both alloys are mainly dissolved as the solid solution temperature increases from 460 °C to 510 °C. The 7085-Sc alloy shows a smaller grain size, higher ultimate tensile strength (UTS, 624 MPa) and yield strength (YS, 580 MPa) after treatment of 480 °C/1 h + 120 °C/24 h. The high strength of 7085-Sc alloy could be attributed to fine-grained strengthening & dislocation strengthening of Al3(Sc, Zr) particles and the precipitation strengthening of MgZn2 phases. The optimum solid solution temperature of 7085 alloy should be controlled in the range of 470–480 °C and that of 7085-Sc alloy is higher, should be 480–490 °C.

The effect of solid solution temperature on the precipitation phase and properties of plasma arc welded joints of Inconel625 high temperature alloy

The effect of solid solution temperature on microstructure and mechanical properties of plasma welded nickel-based high temperature alloy Incone l625 was investigated by solid solution treatment (The solid solution temperature range is 950 °C to 1150 °C and the intergroup interval is 50 °C). The results show that after solid solution treatment at 950 °C, chain carbides are precipitated at the austenite grain boundary of the base material. With solid solution temperature increasing, carbon chains dissolve gradually at the grain boundary. When solution temperature is higher than 1050 °C, carbides at the grain boundary completely melt back into the matrix. At the weld, dendritic crystal and Laves phase dissolve with the increase of solid solution temperature. When the solid solution temperature is 1100 °C, the dendritic crystal and Laves phase at the weld completely melt into the matrix and transform into cellular crystals. When the solid solution temperature is increased to 1150 °C, the cellular crystal grows further at the weld. When the solid solution temperature is 1100 °C, the comprehensive mechanical properties of the joint are the best.

Effects of solid solution temperature on the microstructure and properties of 6013 aluminum alloy

The components as well as the formation and heat treatment processes of the Al–Mg–Si–Cu aluminum alloy have been investigated in detail. However, only a few reports have considered the effects of solid solution treatment on the microstructure and properties of 6013 aluminum alloy during the aging process. In this study, the effects of solid solution temperature on the microstructure and properties of the 6013 aluminum alloy were studied via mechanical property testing, intergranular corrosion testing, electrochemical testing, and scanning and transmission electron microscopy. The results indicated that when the solid solution temperature of the alloy increased from 530 to 570 °C, the residual Mg2Si phase gradually decreased and the quantity of residual Al(FeMn)Si phase did not significantly change. As the solid solution temperature increased, the tensile strength, micro-hardness, and corrosion resistance of the alloy after T6 aging gradually increased, and the elongation and electrical conductivity, in turn, gradually decreased. Transmission electron microscopy depicted that the GP Zones and L phases of the alloy in the T6 state were observed. As the solid solution temperature increased, the quantity of the GP Zones and L phases increased, thereby increasing the material strength. The number of precipitates in the grain boundary gradually decreased, and the distribution distance gradually increased, which attenuated intergranular corrosion.

Effects of solid-solution temperature on microstructure and mechanical properties of a novel 2000 MPa grade ultra-high-strength steel

A novel 2000 MPa grade ultra-high-strength steel AIR0509 with high fracture toughness and low cost has recently been developed. The effects of solid-solution temperature on the microstructure and mechanical properties of this steel were investigated. The increase in solid-solution temperature first increased and then decreased the values of ultimate strength (UTS) and Charpy U-notch (CUN) energy. The increase in the UTS and CUN values was caused by the dissolution of the primary carbides M6C and MC, while the decrease in both strength and toughness was due to the increase in the prior austenite grain size. Samples that were solid-solution treated at 1000 °C exhibited an optimal combination of strength and toughness with a UTS of 2020 MPa, yield strength of 1780 MPa, and CUN energy of 68 J, as well as a correlative fracture toughness KIC value of about 105 MPa m1/2.

Effect of solid-solution temperature on microstructure of incoloy825 alloy and its corrosion behavior in a polluted marine environment

Effect of solid-solution temperature on microstructure of incoloy825 alloy and its corrosion behavior in a polluted marine environment

The effect of solid-solution temperature on phase composition, tensile characteristics and fracture mechanism of V-containing CrMn-steels with high interstitial content C+N>1 mass. %

New high-interstitial austenitic Fe–19Cr–22Mn–1.6V–0.4C–0.8N (mass. %) and Fe–22Cr–26Mn–1.3V–0.7C–1.2N steels were designed. A combination of high interstitial content (C + N = 1.2 mass. % and C + N = 1.9 mass. %, C/N = 0.5–0.6) and V-alloying of these steels provides a complex hardening mechanism (a solid-solution hardening, a particle strengthening and a grain boundary hardening). Increase in solid-solution temperature in the interval 1100–1230 °C forces solid-solution hardening, causes grain growth and changes a distribution and volume fraction of the precipitates in austenite. The relation of these factors governs the value of a yield strength, an ultimate tensile strength and an elongation in the high-interstitial steels. The variation in particle strengthening with solid-solution temperature has minor effect on the yield strength of the steels, but the distribution of precipitates strongly influences a tensile fracture micromechanism of the steels. The effect of solid-solution temperature on fracture peculiarities is described based on microstructural analysis of the steels.

Effect of solid solution temperature on microstructure of Hf-containing K416B Ni-based superalloy with high W-content

Effect of solid solution temperature on microstructure of Hf-containing K416B Ni-based superalloy with high W-content

Effects of Different Solid Solution Temperatures on Microstructure and Mechanical Properties of the AA7075 Alloy After T6 Heat Treatment

Abstract In this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.

Effect of Solid Solution Temperature on Microstructure and Corrosion Resistance of CoNiCrMo Alloy

Influence of solid solution temperature on microstructures and corrosion properties of CoNiCrMo alloy were investigated by means of optical microscopy (OM), scanning electron microscope (SEM) and electronic differential system. The corrosion resistance of CoNiCrMo alloy in 0.9%NaCl aqueous solution was also investigated. The results indicated that with the increase of solution treatment temperature, the dendrites of CoNiCrMo alloy gradually disappeared. Thus, the corrosion resistance of the alloy decreased. When the solution temperature is 1200oC, the dendrites almost disappeared and most carbide dissolved, and begins to spheroidization. The corrosion resistance of CoNiCrMo alloy treated at 1000oC for 1h is the highest than the one at 1100 oC and 1200oC. Its self-corrosion potential is -424mV and self-corrosion current density is 1.02×10-8A/cm2.

Effects of Solid Solution Temperature on the Structure and Properties of TC16 Titanium Alloy Bars

The effects of solid solution temperature on the structures and properties of TC16 titanium alloy bars that made solid solution treatment in 780°C, 800°C, 850°C, 900°C, respectively, the processing time for 30min, then cooled in the air were studied. The results show that during solid solution treatment under 800°C, the alloy structures are the primary ɑ phase and the metastable β phase, while solid solution temperature rise to 800°C, the alloy structures begin to appear ɑ" martensite phase. With the increase of solid solution temperature, the alloy grain grow up somewhat, material tensile strength increases gradually, yield strength firstly decreases and then increases, elongation at break firstly increases and then decreases, percentage reduction of area at break decreases gradually. Solid solution state of TC16 titanium alloy bars are not suitable for cold heading forming, strengthening the titanium alloy must be subsequent artificial aging treatment.

Effect of Solid Solution Heat Treatment on Microstructures of the Third Generation Single Crystal Superalloy DD9

An observation was conducted on the microstructures of as-cast as well as solid solution treated the third generation single crystal superalloy DD9 using optical microscope and SEM. The effects of solid solution temperature and time on the eutectic fractions of γ/γ and size of γ of the alloy were investigated. The results showed that the microstructure of DD9 was uniform. W and Re segregated to the dendrite cores while Al, Ta and Nb were enriched in interdendritic regions during solidification. The eutectic fractions of γ/γ reduced with the solid solution temperature raising and the solid solution time prolonging. When solid solution temperature increased to 1340, the eutectic in the alloy was entirely dissolved. The size of γ in dendritic cores was consistent, however the size of γ in interdendritic regions was gradually decreased with the increase of solid solution treatment and time, eventually the sizes of γ were completely uniform at the temperature of 1340

Effect of solid-solution temperature on the microstructure of Fe-Ni based high strength low thermal expansion (HSLTE) alloy

The influence of solid-solution temperature on the dissolution of carbide precipitates, the average grain size and the micro-hardness of the austenite matrix in an Fe-Ni based high strength low thermal expansion (HSLTE) alloy was investigated to obtain the proper temperature range of the solid-solution process. The XRD analysis, microstructure observations, and the theoretical calculations showed that the Mo-rich M 2C-type precipitates in the Fe-Ni based HSLTE alloy dissolve completely at about 1100°C. The average grain size of the studied alloys increases from 14 to 46 μm in the temperature range of 1050 to 1200°C. The microhardness of the matrix decreases first for the sake of solid-solution treatment, but then increases later with increasing solution temperature because of the solution strengthening effect.

Nitrogen partitioning between matrix, grain boundaries and precipitates in high-alloyed austenitic steels

New high-interstitial austenitic Fe–19Cr–22Mn–1.6V–0.4C–0.8N (mass. %) and Fe–22Cr–26Mn–1.3V–0.7C–1.2N steels were designed. A combination of high interstitial content (C + N = 1.2 mass. % and C + N = 1.9 mass. %, C/N = 0.5–0.6) and V-alloying of these steels provides a complex hardening mechanism (a solid-solution hardening, a particle strengthening and a grain boundary hardening). Increase in solid-solution temperature in the interval 1100–1230 °C forces solid-solution hardening, causes grain growth and changes a distribution and volume fraction of the precipitates in austenite. The relation of these factors governs the value of a yield strength, an ultimate tensile strength and an elongation in the high-interstitial steels. The variation in particle strengthening with solid-solution temperature has minor effect on the yield strength of the steels, but the distribution of precipitates strongly influences a tensile fracture micromechanism of the steels. The effect of solid-solution temperature on fracture peculiarities is described based on microstructural analysis of the steels.