种蛋不同贮存期及贮存期内热处理对孵化指标的影响

为研究不同贮存期及贮存期内热处理对海兰褐父母代种蛋孵化指标的影响，将来源相同的种蛋分别贮存1、2、3、4……17d，其他贮存条件相同。孵化后，分析其孵化指标。包括活胚率、死胚率、毛蛋率、健母雏率和蛋雏比等。另外，对贮存12～17d和10-20d的种蛋在入孵前一天进行热处理，孵化后分析其孵化指标。结果显示：贮存时间过短（1～2d）和过长（9～17d）都会影响种蛋的孵化。在贮存期热处理可提升蛋鸡种蛋的孵化指标，尤其是对贮存10～20d的种蛋。研究结果表明，对贮存时间超过10d以上的种蛋采用贮存期预温刺激的方式可以有效提高种蛋的孵化率和正品率，对规模化孵化厅技术管理具有实际指导作用。

热处理工艺规程编制及查询系统软件开发

介绍了锅炉生产厂的热处理工艺规程微机化管理的实现过程。运用PowerBuilder9.0作为前端开发工具,SQLServer2000作为后台数据库管理工具开发热处理工艺规程编制及查询系统。该系统的成功应用可大大提高热处理工艺规程编制及查询的自动化水平,同时方便热处理工艺规程数据的保留与管理。

SA-335 P91马氏体耐热钢焊接工艺研究

介绍了SA-335 P91马氏体耐热钢的化学成分及力学性能、冶金性能以及正火+回火热处理温度对材料性能的影响。对SA-335 P91钢的焊接性以及焊缝马氏体组织转变进行了分析。焊接工艺评定试验根据产品制造的需求,进行GTAW+SAW焊接试验,根据焊材熔敷金属中镍+锰元素的含量,确定合理的焊后热处理工艺,最终经力学性能试验,得到了力学性能良好的焊接接头,焊接接头硬度值满足标准的要求,焊缝微观组织为回火马氏体。

浅谈渔平高速公路下封层热沥青表处的质量控制

福州渔平高速公路下封层热沥青表处采用先进的施工工艺、试验检测方法进行质量控制,有效地控制了下封层热沥青表处施工质量。

Effect of thermo-mechanical treatment on microstructure and mechanical properties of wire-arc additively manufactured Al-Cu alloy

Wire-arc additive manufacture(WAAM)has great potential for manufacturing of Al-Cu components.However,inferior mechanical properties of WAAM deposited material restrict its industrial application.Inter-layer cold rolling and thermo-mechanical heat treatment(T8)with pre-stretching deformation between solution and aging treatment were adopted in this study.Their effects on hardness,mechanical properties and microstructure were analyzed and compared to the conventional heat treatment(T6).The results show that cold rolling increases the hardness and strengths,which further increase with T8 treatment.The ultimate tensile strength(UTS)of 513 MPa and yield stress(YS)of 413 MPa can be obtained in the inter-layer cold-rolled sample with T8 treatment,which is much higher than that in the as-deposited samples.The cold-rolled samples show higher elongation than that of as-deposited ones due to significant elimination of porosity in cold rolling;while both the T6 and T8 treatments decrease the elongation.The cold rolling and pre-stretching deformation both contribute to the formation of dense and dispersive precipitatedθ′phases,which inhibits the dislocation movement and enhances the strengths;as a result,T8 treatment shows better strengthening effect than the T6 treatment.The strengthening mechanism was analyzed and it was mainly related to work hardening and precipitation strengthening.

Corrosion behavior of 2A97 Al-Cu-Li alloys in different thermomechanical conditions by quasi-in-situ analysis

As a promising material in the aircraft industry,2A97 Al-Cu-Li alloy exhibits high corrosion susceptibility that may limit its application.In the present work,to illustrate the influences of precipitate and grain-stored energy on localized corrosion evolution in 2A97 Al-Cu-Li alloy,cold working and artificial aging were carried out to produce 2A97 Al-Cu-Li alloys under different thermomechanical conditions.Quasi-in-situ analysis,traditional immersion test and electrochemical measurement were then conducted to examine the corrosion behavior of 2A97 alloys.It is revealed that precipitate significantly affects Cu enrichment at corrosion fronts,which determines corrosion susceptibility of alloys,whereas grain-stored energy distribution is closely associated with localized corrosion propagation.It is also indicated that quasi-in-situ analysis exhibits a consistent corrosion evolution with traditional immersion tests,which is regarded as a proper method to explore localized corrosion mechanisms by providing local microstructural information with enhanced time and spatial resolutions.

Effect of substrate temperature and oxygen plasma treatment on the properties of magnetron-sputtered CdS for solar cell applications

Cadmium sulfide(CdS)is an n-type semiconductor with excellent electrical conductivity that is widely used as an electron transport material(ETM)in solar cells.At present,numerous methods for preparing CdS thin films have emerged,among which magnetron sputtering(MS)is one of the most commonly used vacuum techniques.For this type of technique,the substrate temperature is one of the key deposition parameters that affects the interfacial properties between the target film and substrate,determining the specific growth habits of the films.Herein,the effect of substrate temperature on the microstructure and electrical properties of magnetron-sputtered CdS(MS-CdS)films was studied and applied for the first time in hydrothermally deposited antimony selenosulfide(Sb_(2)(S,Se)_(3))solar cells.Adjusting the substrate temperature not only results in the design of the flat and dense film with enhanced crystallinity but also leads to the formation of an energy level arrangement with a Sb_(2)(S,Se)_(3)layer that is more favorable for electron transfer.In addition,we developed an oxygen plasma treatment for CdS,reducing the parasitic absorption of the device and resulting in an increase in the short-circuit current density of the solar cell.This study demonstrates the feasibility of MS-CdS in the fabrication of hydrothermal Sb_(2)(S,Se)_(3)solar cells and provides interface optimization strategies to improve device performance.

Effects of heat treatment on microstructure and mechanical properties of ZK60 Mg alloy

The microstructure and mechanical properties of ZK60 Mg alloy were investigated under different solution treatments and artificial aging conditions. When as-cast ZK60 alloy was solution treated at 400 ℃for 10 h and artificially aged at 150 ℃, the volume fraction of precipitates increased with the aging time up to 30 h. When the as-cast ZK60 alloy was solution treated at 400 ℃ for 10 h and artificially aged at 200 ℃ for 15 20 h, the volume fraction of precipitates reached a peak value. Tensile test at room temperature showed that a high density of the second phase precipitates was beneficial to improving the strength and elongation. Solution treatment at 400 ℃ for 10 h and artificial aging at 150 ℃ for 30 h is considered the optimum heat treatment condition to obtain a good combination of strength and ductility.

Effect of heat treatment on stress corrosion cracking, fracture toughness and strength of 7085 aluminum alloy

The influences of heat treatment on stress corrosion cracking （SCC）, fracture toughness and strength of 7085 aluminum alloy were investigated by slow strain rate testing, Kahn tear testing combined with scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results show that the fracture toughness of T74 overaging is increased by 22.9% at the expense of 13.6% strength, and retrogression and reaging （RRA） enhances fracture toughness 14.2% without reducing the strength compared with T6 temper. The fracture toughness of dual-retrogression and reaging （DRRA） is equivalent to that of T74 with an increased strength of 14.6%. The SCC resistance increases in the order： T6〈RRA〈DRRA≈T74. The differences of fracture toughness and SCC were explained on the basis of the role of matrix precipitates and grain boundary orecioitates.

Comparison of mechanical properties in high temperature and thermal treatment granite

Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious form, stress-strain curve, peak strength, peak strain and elastic modulus with temperature were analyzed and the essence of rock failure modes was explored. The results indicate that, compared with granite after the high temperature treatment, the brittle-ductile transition critical temperature is lower, the densification stage is longer, the elastic modulus is smaller and the damage is larger under high temperature. In addition, the peak stress is lower and the peak strain is greater, but both of them change more obviously with the increase of temperature compared with that of granite after the high temperature treatment. Furthermore, the failure modes of granite after the high temperature treatment and under high temperature show a remarkable difference. Below 100 ℃, the failure modes of granite under both conditions are the same, presenting splitting failure. However, after 100 ℃, the failure modes of granite after the high temperature treatment and under high temperature present splitting failure and shear failure, respectively.

Microstructure and mechanical properties of as-quenched Mg-Gd-Zr alloys

Mg-xGd-0.6Zr （x=2, 4, 6, mass fraction） alloys were prepared by semi-continuous casting process. The effects of Gd content on the microstructures and mechanical properties of Mg-xGd-0.6Zr alloys were studied and the solid solution treatment process of Mg-6Gd-0.6Zr alloys was optimized. The microstructures and mechanical properties of all the studied alloys were analyzed by optical microscope, X-ray diffraction, scanning electron microscope equipped with energy dispersive spectroscope and micro-hardness tester. The results show that the grain size slightly decreases with increasing Gd content and there is a close linear relationship between Gd content and micro-hardness of Mg-xGd-0.6Zr alloys. The second phases Mg 2 Gd and Mg 3 Gd formed due to non-equilibrium solidification during the casting process can be transformed into equilibrium phase Mg 5.05 Gd which can dissolve into α-Mg solid solution phase at solution temperature of 460 ℃ The optimized solid solution treatment of Mg-6Gd-0.6Zr alloy is （300 ℃ 6 h） ＋ （460 ℃ 10 h）.

Microstructure and mechanical properties of TC21 titanium alloy after heat treatment

Microstructure evolutions during different heat treatments and influence of microstmcture on mechanical properties of TC21 titanium alloy were investigated. The results indicate that the excellent mechanical properties can be obtained by adopting air cooling after forging followed by heat treatment of （900℃, 1 h, AC）＋（590 ℃, 4 h, AC）. Deformation in single β field produces pan-like prior fl grains, while annealing in single fl field produces equiaxed prior fl grains. Cooling rate after forging or annealing in single fl field and the subsequent annealing on the top of α＋β field determine the content and morphology of coarse a plates. During aging or the third annealing, fine secondary a plates precipitate. Both ultimate strength and yield strength decrease with the content increase of coarse a plates. Decreasing effective slip length and high crack propagation resistance increase the plasticity. The crisscross coarse a plates with large thickness are helpful to enhance the fracture toughness.

Microstructure of cast γ-TiAl based alloy solidified from β phase region

The microstructures and phase transformation of Ti-43Al-4Nb alloy in as-cast and heat-treated states were investigated by using optical microscopy, scanning and transmission electron microscopy as well as differential scanning calorimetry. The results show that a fine microstructure of the as-cast alloy can be obtained by solidifying through the β phase. γ grains can nucleate directly from the β phase. The coexistence of β phase and γ phase along primary α grain boundaries contributes to the decrease in the grain size of the as-cast alloy. The phase transformation sequence during solidification of the Ti-43Al-4Nb alloy is suggested as L→L＋β→β→α＋β→α＋βr→α＋γ＋βr→lamellae（α2＋γ）＋γ＋βr. The microstructure of the alloy after heat treatment at 1 250 ℃ for 16 h exhibits a certain coarsening compared with that of the as-cast state. The remnant β phase can be removed by the heat treatment process due to the diffusion of Nb and the non-equilibrium state of β phase.

Microstructure evolution and thermal expansion of Cu-Zn alloy after high pressure heat treatment

The thermal expansion coefficients of Cu-Zn alloy before and after high pressure treatment were measured by thermal expansion instrument in the temperature range of 25？700 ℃,and the microstructure and phase transformation of the alloy were examined by optical microscope,X-ray diffractometer（XRD） and differential scanning calorimeter（DSC）.Based on the experimental results,the effects of high pressure treatment on the microstructure and thermal expansion of Cu-Zn alloy were investigated.The results show that the high pressure treatment can refine the grain and increase the thermal expansion coefficient of the Cu-Zn alloy,resulting in that the thermal expansion coefficient exhibits a high peak value on the α-T curve,and the peak value decreases with increasing the pressure.

Effect of heat treatment on microstructure and tensile properties of A356 alloys

Two heat treatments of A356 alloys with combined addition of rare earth and strontium were conducted.T6 treatment is a long time treatment（solution at 535 ℃ for 4 h ＋ aging at 150 ℃ for 15 h）.The other treatment is a short time treatment（solution at 550 ℃ for 2 h ＋ aging at 170 ℃ for 2 h）.The effects of heat treatment on microstructure and tensile properties of the Al-7%Si-0.3%Mg alloys were investigated by optical microscopy,scanning electronic microscopy and tension test.It is found that a 2 h solution at 550 ℃ is sufficient to make homogenization and saturation of magnesium and silicon in α（Al） phase,spheroid of eutectic Si phase.Followed by solution,a 2 h artificial aging at 170 ℃ is almost enough to produce hardening precipitates.Those samples treated with T6 achieve the maximum tensile strength and fracture elongation.With short time treatment（ST）,samples can reach 90% of the maximum yield strength,95% of the maximum strength,and 80% of the maximum elongation.

Intermetallic phase evolution of 5059 aluminum alloy during homogenization

Intermetallic phase evolution of 5059 aluminum alloy during homogenization was investigated by means of optical microscopy （OM）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, energy dispersive spectrometry （EDS）, differential scanning calorimetry （DSC） and X-ray diffraction analysis （XRD）. The results show that severe dendritic segregation exists in as-cast alloy. The dissolvable intermetallic phases in as-cast alloy consist of Zn-and Cu-rich non-equilibriumβ（Al3Mg2） phase, Fe-rich eutectic Al6Mn phase and equilibrium Mg2Si phase. During the homogenization, Zn- and Cu-rich non-equilibrium β （Al3Mg2） phase, Fe-rich eutectic Al6Mn phase and equilibrium Mg2Si gradually dissolve into matrix. Fine dispersed β（Al3Mg2） particles and rod-shaped Al6Mn particles form in the Al matrix after homogenization. The proper homogenization processing is at 450 °C for 24 h, which is consistent with the results of homogenizing kinetic analysis.

Effect of heat treatment on microstructures and mechanical properties of sand-cast Mg-10Gd-3Y-0.5Zr magnesium alloy

The microstructure, mechanical properties and fracture behavior of sand-cast Mg-10Gd-3Y-0.5Zr alloy （mass fraction,%） under T6 condition （air cooling after solid solution and then aging heat treatment） were investigated. The optimum T6 heat treatments for sand-cast Mg-10Gd-3Y-0.5Zr alloy are （525 ℃, 12 h＋225 ℃, 14 h） and （525 ℃, 12 h＋250 ℃, 12 h） according to age hardening curve and mechanical properties, respectively. The ultimate tensile strength, yield strength and elongation of the Mg-10Gd-3Y-0.5Zr alloy treated by the two optimum T6 processes are 339.9 MPa, 251.6 MPa, 1.5%and 359.6 MPa, 247.3 MPa, 2.7%, respectively. The tensile fracture mode of peak-aged Mg-10Gd-3Y-0.5Zr alloy is transgranular quasi-cleavage fracture.

Effect of heat treatment on microstructure and mechanical property of Ti-steel explosive-rolling clad plate

The effect of heat treatment on microstructure and mechanical properties of the Ti-steel explosive-rolling clad plate was elaborated by optical microscopy （OM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, micro-hardness test and shear test. The composites were subjected to heat treatment at temperature of 650-950 ~C for 60 min. The results show that the heat treatment process results in a great enhancement of diffusion and microstructural transformation. The shear strength decreases as the treatment temperature increases. Heated at 850 ℃ or below, their shear strength decreases slowly as a result of the formation of TiC in the diffusion interaction layer; while at the temperature of 850 ℃ or above, the shear strength decreases obviously, which is the consequence of a large amount of Ti-Fe intermetaUics （Fe2Ti/FeTi） along with some TiC distributing continuously at diffusion reaction layer.

Microstructural evolution of 2026 aluminum alloy during hot compression and subsequent heat treatment

2026 aluminum alloy was compressed in a temperature range of 300-450 ℃ and strain rate range of 0.01-10 s^-1. The correlation between compression conditions and microstructural evolution after solution and aging heat treatment was investigated. It is found that the recrystallization and precipitation behavior after heat treatment are associated with the temperature compensated strain rate Z value during hot deformation. Under low Z parameter condition, a small quantity of free recrystallized grains are formed, and the well formed subgrains with clean high-angle boundaries and coarse precipitates seem to be remained during heat treatment. Under high Z parameter condition, a large number of fine equiaxed recrystallized grains are produced, and a high dislocation density with poorly developed cellularity and considerable fine dynamic precipitates are replaced by the well formed subgrains and relatively coarse precipitates after heat treatment. The average recrystallized grain size after heat treatment decreases with increasing Z value and a quantitative relation between the average grain size and the Z value is obtained.

Effects of heat treatment on microstructure and mechanical properties of ZA27 alloy

The effects of heat treatment on the microstructure and mechanical properties of ZA27 alloy were studied by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and mechanical characterization.The results indicated that the as-cast microstructure of the alloy was mainly composed of α,decomposed β,η and ε phases.After solid solution treatment at 365 ℃ for 1 h,α and η phases dissolved,and the microstructure of specimen was mainly composed of the supersaturated β phases.The phase decomposition of supersaturated ZA27 alloy is a two-stage phase transformation：the decomposition of the supersaturated β phase at the early stage of aging,and with the increase of aging time,ε phase decomposition through a four-phase transformation：α＋ε→T ＇＋ η.A good combination of high tensile elongation and reasonable strength can be achieved by suitable heat treatments.