光学加工对GaAs窗口晶体断裂模数的影响

用四点弯曲法测量了GaAs晶体断裂模数 ,其结果表明加工方法是影响GaAs晶体断裂模数测量值的重要因素。切割加工的GaAs晶体的断裂模数最低 ,研磨加工GaAs晶体的断裂模数其次 ,机械抛光的断裂模数再其次 ,而机械抛光后再化学抛光的GaAs晶体的断裂模数平均值最高 ,其平均值约为 135MPa。光学加工表面损伤层及损伤层中的缺陷、裂纹和应力将导致GaAs晶体的断裂模数值下降。     

锗晶体断裂模数的测试

用四点弯曲法测量了锗单晶和多晶样品（３６ｍｍ×４ｍｍ×３ｍｍ）的断裂模数，其结果与美、英、比等国家公布的数据基本相符．实验证明样品表面加工方法是影响测量值的重要因素；机械应力和热应力将导致断裂模数的下降。     

VGF法GaAs单晶位错分布的数值模拟和Raman光谱研究

采用数值模拟技术和Raman光谱法对4inch垂直梯度凝固(VGF)法GaAs单晶位错进行了研究。运用数值模拟软件计算了GaAs晶体生长过程中的位错分布,模拟计算与实验结果一致。通过Raman光谱测量,定量计算了晶片表面的残余应力分布。Raman测量结果表明,残余应力与位错密度分布基本一致。在VGF法生长的GaAs单晶中观察到了不完整的位错胞状结构,并利用Raman光谱法对其进行了微区分析。     

TC17钛合金叶片制造过程的表面完整性研究

采用多种最终加工工序组合,在TC17钛合金叶片表面引入不同表面完整性状态,研究最终加工工序对叶片表面形貌、平均粗糙度、残余应力的影响。结果表明:仅振动光饰处理后,表面平均粗糙度在0.2μm以下,表面残留有磨料运动痕迹,残余应力影响层深度约为30~40μm,表面残余应力仅-200 MPa左右;不进行振动光饰处理时,陶瓷丸喷丸比玻璃丸喷丸后叶片表面粗糙度更佳,喷丸后叶片表面Kurtosis值接近3,本研究中残余应力影响层深度约为100μm,表面残余应力在-750~-850 MPa之间;喷丸后进行振动光饰可消除叶片表面的喷丸弹坑,平均粗糙度减小到0.2μm以下,残余应力影响层深度与未经振动光饰处理的相当,表面残余应力变化小。当加工痕迹被喷丸消除时,叶片表面Kurtosis值接近3,这说明弹坑底部圆滑,因此认为Kurtosis值可作为表征喷丸表面的特征粗糙度参数。     

基于数值模拟的ZM6合金铸造与退火过程残余应力演变研究

利用有限元软件procast和abaqus分别对阶梯型零件进行铸造和退火过程进行热力学仿真模拟,得到阶梯型零件的残余应力的分布情况和变化趋势。结果表明,退火前后,零件残余应力服从,零件表面为压应力,零件内部为拉应力的规律。铸件在退火后,残余应力值降低,且应力值波动幅度减弱。同时,用X射线衍射法对样品零件进行了应力值测量,将实测值与仿真值进行对比分析,两者契合度较高。     

TC4钛合金MIG焊接头热处理后组织性能研究

对TC4钛合金MIG焊焊接接头进行焊后热处理,采用盲孔法、拉伸、冲击、金相、扫描等方法对接头进行试验与分析,研究不同热处理工艺对残余应力、组织和力学性能的影响.结果 表明:焊接接头经焊后热处理,横向残余应力和纵向残余应力平均值最大降为74.2 MPa和70.1 MPa;未热处理接头母材区为α+β片层组织,焊缝区为α针状马氏体组织,热影响区为α和α'混合组织.热处理后,随着热处理温度和时间的增加,焊缝组织中的针状α'马氏体粗化,晶粒尺寸增加;未热处理接头焊后拉伸断裂位置为母材处,接头强度高于母材.在650℃+2 h的热处理工艺下,接头延伸率较未热处理状态提高,断裂方式为韧性断裂,保温时间延长至3h,晶粒粗大、延伸率降低.接头室温冲击功焊后状态能够达到母材的95％,经焊后热处理后接头得到软化,室温冲击功相比焊后状态有所下降.     

电力机车电动机轴断裂原因的分析

简要从微观角度分析了电力机车电动机轴的断裂原因,认为轴断裂与焊接后产生残余应力及焊后未经过退火处理有直接关系。     

316Ti不锈钢钢管残余应力分析

用钻孔贴应变片法对316Ti不锈钢管进行残余应力的测量;研究比较了冷轧态、退火态、冷矫直状态对残余应力的影响。试验结果表明:316Ti不锈钢钢管经冷轧加工其残余应力增加到接近屈服强度;经固熔热处理材料的残余应力明显下降,但因冷却及材料内部组织不均匀仍存在周向压应力;矫直变形会增加316Ti不锈钢钢管的残余应力,周向因矫直变形,表面压应力消失;Φ25.0 mm×2.0 mm规格小管热处理冷却过程中弯曲度大,因此矫直后残余应力增加较大。     

深冷对逆相变处理中锰钢组织性能的影响

为了研究原始组织状态对逆相变退火中锰钢微观组织和力学性能的影响,对淬火处理的中锰钢再进行-74℃深冷处理,采用SEM、EBSD、XRD等手段评价了逆相变退火处理后的微观组织,用单轴拉伸和冲击试验评价力学性能。研究结果表明:淬火态中锰钢的组织由马氏体和体积分数约为33%的残余奥氏体组成,深冷处理后得到残余奥氏体体积分数小于15%的细小马氏体组织;相对于淬火+逆相变处理的样品,深冷+逆相变样品奥氏体体积分数从31%提高到49%,具有更高的奥氏体稳定性使屈服强度从650 MPa提高到852 MPa,断后伸长率从22%提高到37%。     

快速热退火对GaInNAs/GaAs单量子阱反常温度特性研究

分析了MBE生长的GaInNAs／GaAs单量子阱样品的光致荧光谱(PL)，细致地研究了在弱激发功率下GaInNAs／GaAs样品的发光峰位的S-型反常温度依赖关系。并对材料进行了退火处理，结果发现退火有效地改善材料的发光特性，并且会造成S-型的转变温度降低，从而说明退火可以有效地减少局域态。     

1750mm冷连轧精冲钢的连续退火工艺

连续退火工艺制度是精冲钢冷连轧生产过程中的重要环节,对其成品组织性能有着极其重要的影响。在实验室进行轧制润滑试验研究,设计了多种连续退火工艺方案,采用CAS- 300连续退火试验机模拟连续退火试验,确定了C15/2精冲钢的再结晶温度为550℃。针对不同规格冷连轧精冲带钢,通过拉伸试验和显微组织鉴定,给出了适用于冷连轧生产实践的连续退火工艺制度。结果表明,退火后试样的屈服强度控制在(310±20)MPa,抗拉强度小于450MPa,伸长率大于30%,获得了良好综合力学性能的精冲钢组织。该研究完全满足工业生产实践的需求,对精冲钢冷连轧生产退火工艺研究具有重要意义。     

Control of UFG Microstructure in Welded Carbon Steel Tubes by Cold Drawing and Annealing

The present study is made to develop ultra fine grained microstructure in welded steel tubes, through multiple cold drawing passes followed by an annealing treatment. The average ferrite grain size is reduced from 16 to 1.9 μm. SAE 1019M steel grade used for a typical automotive driveline component is studied. Strains between 0.3 and 1.4 followed by annealing at 400, 450 and 500 °C are considered to optimize the combination of cold drawing strain and temperature required to produce ultra fine grained microstructure in steel tubes. At a strain value of 1.4 and annealing temperature, 500 °C, polygonal ferrite grains and fine carbide particles are obtained. This microstructure is found to be suitable owing to its combination of high strength and good ductility in steel tubes. Tensile strength as high as 1,061 MPa and 9 % elongation is obtained due to microstructural refinement. The strength is increased by 350 MPa compared to the strength of conventional cold-drawn welded tubes.     

高温与应力耦合作用下Cr-Co-Mo-Ni齿轮轴承钢微观组织演变

 对热处理态的高温Cr-Co-Mo-Ni齿轮轴承试验钢在500℃下进行不同应力的持久试验,采用内插法得到500℃,500h的断裂强度为1022MPa;借助金相显微镜、扫描电镜和透射电镜等仪器观察试验钢持久试验前后的微观组织变化。结果表明：500℃条件下,随着加载持久应力由1150MPa降低至950MPa,试验钢断裂时间由96.4h延长至845.8h,基体中碳化物平均尺寸由0.3μm长大到0.5μm以上,所占面积分数由1.65%上升至3.85%;随着持久应力的降低及断裂时间的延长,马氏体板条束发生剪切变形—碎化—重新排列的变形过程,位错密度呈下降趋势;持久断裂前后,试验钢基体中析出相均为M6C型碳化物。     

非掺半绝缘LEC-GaAs晶片热处理工艺研究

为了获得高质量半绝缘砷化镓单晶片．有必要降低微缺陷密度，开展了晶片热处理工艺的研究．确定了晶片热处理的温度、时间、降温建率等一系列工艺参数，证实丁采用此项工艺能降低LEG-GaAs晶片的砷沉淀密度，郎AB-EPD，同时也保证了晶片的电学参数不受影响。通过对晶片热处理工艺过程和结果进行分析．给出了晶片热处理工艺理论模型的解释。     

Creep deformation of Ni3Al-Mo in situ composites

High temperature γ′(Ni₃A1)-α(Mo) in situ composites solidified with growth rates ranging from 0.12 cm/h to 2.4 cm/h, were creep tested at temperatures 710 °C, 830 °C, and 950 °C under a tensile stress of 300 MPa. Creep rupture lives of rapidly grown alloys were comparable to those of γ′/γ-δ and Nitac eutectics whereas strain to rupture was up to three times greater. In comparison, creep rupture lives of slowly grown alloys were more than ten times and strain to rupture about two times smaller than in rapidly grown alloys. In slowly grown alloys, failure occurred by formation of shear bands caused by cooperative shear of matrix and fibers whereas no shear bands were seen in rapidly grown samples. Shear band formation was due to pile-up stresses and parallel orientation of matrix and fiber slip systems, the latter resulting from a change in the crystallographic phase relationship as growth rate decreased. There was evidence that shear band formation depended on a threshold stress. The creep behavior of rapidly grown alloys was in qualitative agreement with predictions obtained from a linear visco-elastic model composite strengthened by the “mean matrix stress”.     

IF钢晶体取向与纳米力学性能的原位分析

为了研究材料微区力学性能与多晶体取向之间的直接定量联系,以IF钢(无间隙原子钢)为例,分析了不同晶体取向与纳米力学性能之间的关系。首先利用高温激光扫描共聚焦显微镜(HLSM)对IF钢样品进行退火处理,以保证原位分析的有效性,然后通过电子背散射衍射(EBSD)对退火前后的标定区域进行晶体取向分析,得出晶体取向的原位变化规律,最后利用纳米压痕仪测试标定区域的微观力学性能。结果表明,不同晶体取向晶粒的杨氏模量不同,在原子间距较小的<111>晶体学方向上,杨氏模量值较高,在原子间距较大的<001>晶体学方向上,杨氏模量值较低,并通过理论计算验证了试验结果。退火后,不同晶体取向的晶粒硬度没有明显的规律性,但晶粒内位错密度显著降低,硬度比冷轧态明显下降,随着退火温度的升高,硬度降低速度变缓。     

Effect of Thickness and Annealing Temperature on Magnetic Properties of Ultrathin γ-Fe2O3 Films Grown on Silicon Substrate

The effect of thickness and annealing temperature on magnetic properties of ultrathin γ-Fe₂O₃ films with MgO buffer layer grown on silicon substrate is investigated. The saturation magnetization and coercive force of samples at room temperature increase with increasing of annealing temperature, and decrease as annealing temperature is above 873 K (600 °C). The saturation magnetization of samples decreases with increasing of the thickness of γ-Fe₂O₃ at room temperature. The samples with 3 to 4 nm thick γ-Fe₂O₃ annealed at 873 K (600 °C) show saturation magnetization of about 400 emu/cm³, which is close to the bulk value of ~390 emu/cm³ within the error range.     

两相区退火温度对TRIP钢组织性能的影响

 针对600 MPa级别TRIP钢,进行了760、780、800、820、840、860 ℃两相区退火温度试验,利用扫描电镜和拉伸试验机等设备,分析了其对应的组织比例和力学性能检验结果,得出结论：随着两相区退火温度的升高,铁素体体积分数逐渐减少,钢板的抗拉强度值不断增加,但伸长率值却先下降再升高,在820 ℃伸长率有最大值,这与820 ℃时较高残余奥氏体体积分数和最大残奥中碳质量分数相对应,说明TRIP效应可以改善钢板的塑性指标,获得最佳强塑组合;在800～820 ℃的两相区转变温度范围内,强塑积可以达到2.17×104 MPa·%,为600 MPa级TRIP钢退火工艺提供了实际指导。     

Determination of Optimal Recrystallization Annealing Temperature of Nb-Ti Microalloyed High Strength IF Steel

The Nb-Ti microalloyed high strength IF steel sheet was used to study the effect of annealing temperature on the microstructures,mechanical properties and textures.The experimental results show that experimental steel is incomplete recrystallization at 750℃ annealing,but complete recrystallization from 780℃ to 870℃ under experimental conditions.When the annealing temperature was increased,the yield strength and tensile strength would gradually reduce,the plastic strain ratio and yield point elongation would gradually increase.The yield strength,tensile strength,elongation,the plastic strain ratio and the strain hardening exponent were approximate 300MPa,410MPa,36.5%,1.7 and 0.22 respectively under annealing temperature 810℃ to 840℃.When the annealing temperature was increased,the α-textures and γ-textures were gradually weakened,and the α-textures have a trend to {111} texture.Therefore,the suggestion of the optimal recrystallization annealing temperature is about 810℃ to 840℃ in industrial production.