退火温度对冷变形Ti_(50)Ni_(45)Cu_5形状记忆合金马氏体相变及力学性能的影响

使用透射电镜(TEM),动态热机械分析(DMA)以及示差扫描量热法(DSC)等测试方法对固溶态25%冷变形Ti_(50)Ni_(45)Cu_5合金400℃/1 h,500℃/1 h,600℃/1 h,700℃/1 h退火态的组织结构,马氏体相变特征以及力学性能进行分析,并在实验中对比使用DSC与DMA两种测试方法用于马氏体相变测试。结果表明,随着退火温度升高,Ti50Ni45Cu5合金的强度、硬度降低,塑性升高,400℃/1 h退火态合金有最高的强度和硬度,分别为996 MPa和HV 280,700℃/1 h退火态合金有最好的延伸率27.8%。随着退火温度升高,合金的马氏体相变温度因为合金内位错密度降低,孪晶晶界减少及内应力减少,逐渐从54.5℃下降至37.7℃。400℃/1 h,500℃/1 h,700℃/1 h退火态合金均发生B19-B19'马氏体相变,而600℃/1 h退火态合金由于Ti3Ni4相的析出B2-B19'马氏体相变转变为B2-B19-B19'两步马氏体相变。两步马氏体相变的B2-B19相变部分和B19-B19'相变部分均在DMA模式测试出,而DSC模式只检测出B2-B19相变部分,DMA模式更适合于本实验测试马氏体相变。     

淬速对Nd_9Fe_(70)Ti_3C_1Nb_3B_(14)快淬薄带晶化相变和磁性能的影响

采用不同的淬速(辊速Vs=10,15,20,25,30 m·s-1)制备了Nd_9Fe_(70)Ti_3C_1Nb_3B_(14)合金快淬薄带,并研究了薄带的晶化相变及其退火后的磁性能随快淬速度提高而发生的变化。结果表明:在淬速15和20 m·s-1之间有一个临界淬速,在临界淬速以下制备的低淬速薄带由非晶和少量Nd_2Fe_(14)B,Fe3B和α-Fe纳米晶组成,而在临界淬速以上制备的高淬速薄带由完全非晶构成。随着淬速的提高,薄带中非晶的热稳定性逐步提高。低淬速薄带晶化过程的相变为AP+Nd_2Fe_(14)B+Fe_3B+α-Fe→Nd_2Fe_(14)B+Fe_3B+α-Fe+Nd_3Fe_(20)B_2→Nd_2Fe_(14)B+Fe_3B+α-Fe,而高淬速薄带晶化过程的相变为AP→AP'+Nd_3Fe_(20)B_2→Fe_3B+Nd_3Fe_(20)B_2→Nd_2Fe_(14)B+Fe_3B+α-Fe。优化退火后,尽管不同淬速薄带的剩磁差别不大,但低淬速薄带的最佳矫顽力和磁能积分别比高淬速薄带的高28.41%和20.12%。     

不同工艺处理对Ni_(50.6)Ti_(49.4)合金相变及形状记忆效应的影响

本文系统地研究了时效、热循环等对Ni_(50.6)Ti_(49.4)合金相变及形状记忆效应的影响。结果表明,马氏体相变和R相变的开始点M_S和TR_s均随合金时效时间的延长而升高到一定值。热循环使淬火后不经其它处理的样品的M_3s降低,而TR_s不变。经过充分时效处理的样品,其M_sM、TR_s在循环过程中保持稳定。通过时效、冷加工、淬火后热循环处理的样品,均能使该合金的R相变与马氏体相变分离。但当采用后两种方法处理时,这两个相变仍相距较近。时效则能使二者相距较远,而且R相变的热滞较小,M_s、TR_s稳定。实验证实,仅在p(?)R相变范围内,虽有较好的单程形状记忆效应,但难以训练出显著的双向记忆效应。     

V2Ti0.5Cr0.5Ni1-xMnx(x=0.05～0.2)储氢合金结构和电化学性能研究

为了研究V基储氢材料的结构和电化学性能,采用真空感应电弧炉熔炼了V_2Ti_(0.5)Cr_(0.5)Ni_(1-x)Mn_x(x=0.05～0.2)储氢合金,并分析该储氢合金电极的微观形貌和电化学性能。结果表明,储氢合金主要由体心立方(BCC)结构的钒基固溶体主相和部分TiNi第二相构成。电化学测试表明,当合金电极中Mn替代Ni的量逐渐增加,储氢合金电极的高倍率放电性能、最大放电容量和交换电流密度逐渐增大,当x=0.2时,合金放电容量最大值为429.3 mAh/g,高倍率放电性能为55%,交换电流密度为52 mA/g,而储氢合金电极的循环稳定性能降低。     

退火温度对TiNi合金记忆性能的影响

用扭转形变—电阻—温度测量装置对 Ti-50.7at%Ni 合金丝在不同温度下时效1h 后的8个样品进行扭转角、相对电阻随温度和时间的同步测量结果为:未发生再结晶的样品(t_a<590℃),R 相稳定,R/R_0—t 曲线中的 t_R-M_S 温区宽。滞后回线面积大,SME 恢复率高;已发生再结晶的样品(t_a>590℃),结果相反。升温时扭转角与时间的关系为:θ=Aexp(-kt~n)+B,对于 t_a 不同的样品,k、n 不同,这与亚稳相 Ti_(11)Ni_(14)引起的晶格畸变和内部缺陷对 R 相稳定性及 M→R 相变的影响有关。     

Ti3Al—Nb合金的组织结构分析

用透射电子显微术和X射线能谱术分析了Ti_3Al-Nb合金在不同热处理状态下的组织结构。结果表明。添加铌使Ti_3A1基合金的铸态组织中的α_2相晶粒中的有序畴细化。Ti_3Al-11Nb合金从高温缓冷到室温的组织由粗大的α_2相晶粒和晶间的β相晶粒组成。Ti_3Al-10Nb合金从1200℃空冷、油淬和水淬到室温后,组织(主要或全部)分别为α_2相、马氏体相+B2相,B2相组成。油淬样品在750℃时效时沿晶界和晶内析出不同形态的α_2相。α_2相晶粒及其内部的有序畴在时效过程中长大。     

形变热处理对Cu-0.7Fe-0.12P合金组织和性能的影响

通过硬度、电导率、光学显微镜和透射电镜等测试手段分析Cu-0.7Fe-0.12P合金的性能与组织,研究形变及时效处理对其组织与性能的影响,得出冷变形量与热处理工艺的优化组合,为该合金的实际生产提供参考。合金经900℃固溶并40%冷轧、450℃时效6 h、70%冷轧后,在400、450和500℃分别时效1 h。研究结果表明,在450℃时效合金的硬度(141 HV)和相对电导率(89.9%IACS)均达到了较好的状态;而直接对合金冷轧变形80%并在450℃下时效1 h后,相对电导率为70%IACS,比经双冷轧双时效处理后测得的合金相对电导率小。     

退火对V-4Cr-4Ti合金微观组织结构的影响

为了解高温退火前后V-4%Cr-4%Ti(记为V-4Cr-4Ti,下同)合金微观组织结构的变化,将合金在1000～1400℃,1×10-2Pa条件下退火不同时间(1h或3h)后,利用透射电子显微镜(TEM)分析了退火前后合金中位错、层错及孪晶的形态。分析结果表明,铸态合金中含有少量的层错和孪晶,但位错密度较高。高温退火后合金中的位错密度降低,层错、扩展位错的密度增加。孪晶密度随退火温度和退火时间的增加而增加。1200℃退火合金中的层错呈现规则的平行排列,层错使得基体衍射点发生分裂;孪晶的孪生面为钒的{211}晶面。在1300℃/3h退火合金中观察到了由大量微孪晶和位错组成的类"马氏体"结构。     

Ni/Ni_3Al两相合金箔材的退火行为研究

研究了冷轧变形95%的Ni/Ni3Al两相合金箔材在经过100h退火后的再结晶过程以及织构和晶粒的微取向的变化。对其织构的测量未表现出如冷轧单相Ni3Al合金退火后所具有的织构记忆效应。EBSD(electron back-scattered diffraction)的测量结果显示退火后根据晶粒的取向可分为两个区域,一个区域的晶粒保持了与冷轧后试样的晶粒相同的取向,即其取向为(110),并且这一区域沿轧制方向呈带状分布,而另一个区域的晶粒的取向则为随机的。两个区域中(110)取向晶粒所占的百分比依次为57%和16%,并且在长时间退火后这种带状结构依然存在。冷轧变形95%的Ni/Ni3Al两相合金箔材在600～800℃之间退火时存在两种再结晶过程。一部分区域退火后生成大量的晶粒取向随机分布的再结晶晶粒,而在另一部分区域则其再结晶晶粒保持与冷轧织构相同的晶粒取向,并随着退火温度的升高而长大。     

形变时效对Cu-1.3Ni-0.3Si合金力学性能及导电率的影响

采用OM、SEM和EDS等分别研究了400~550℃、1~8h时效工艺对冷轧变形程度为0~70%的Cu-1.3Ni-0.3Si合金显微组织及性能的影响。结果表明,经不同冷变形量的合金在450℃时效1h后,硬度均到达峰值,当温度升高到500℃时,合金导电率达到最大值,此时基体组织中分布有大量细小弥散的第二相颗粒;合金的导电率随保温时间的延长不断增大,且变形程度越大,导电率提升越明显。预冷变形量为70%的合金在450℃×3h时效后,其硬度达到180HB,导电率可达52%IACS,相比未经变形合金时效后最高硬度提高了约21%,导电率提高了约11%。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.