制样方法对IF钢纳米压入测试结果的影响

 对3种不同方法制备的IF钢试样进行了纳米压入表征,分析了制样方法对IF钢中铁素体纳米压入测试结果的影响。结果表明,制样方法对铁素体杨氏模量平均值影响不大,但对硬度平均值影响显著,机械抛光和机械抛光+化学侵蚀状态铁素体的硬度均高于机械抛光+电解抛光状态的铁素体。这主要是因为机械抛光对试样表面造成了明显的加工硬化层,而化学侵蚀处理不能完全去除硬化层,只有电解抛光才能起到有效消除硬化层的作用。机械抛光+电解抛光处理更有利于IF钢的纳米压入表征。     

钢中细小夹杂物的研究方法探讨

以氧化物冶金领域中研究最为广泛的钛脱氧产物为例,通过扫描电镜(SEM)对金相试样和电解夹杂物的观察,大样电解萃取夹杂物后X射线衍射(XRD)分析,金属薄膜法制样的透射电镜(TEM)分析,采用离子减薄技术后的电子背散射衍射(EBSD)分析和通过采用RTO法制样的透射电镜分析,对细小夹杂物的研究方法尤其是内部结构和物相组成的研究进行了探讨。实践表明,小样电解是提取钢中细小夹杂物的最好方法,而大样电解可能对夹杂物造成损害。微米级夹杂物采用金属薄膜法制样比较困难,但采用离子减薄后,在SEM下可清晰的观察夹杂物的内部结构并采用EBSD分析其相组成。     

烧结工艺对钛合金汽车零件性能的影响

采用不同的烧结温度和烧结压力对Ti-6Al-4V-0.5In钛合金汽车零件试样进行放电等离子烧结处理,研究了烧结工艺对试样耐磨损性能和冲击性能的影响。结果表明:随烧结温度的提高和烧结压力的增大,试样的耐磨损性能和冲击性能均先提高后下降。钛合金汽车零件材料的烧结温度优选为875℃,烧结压力优选为45 MPa。     

提高LED钨铜散热基板表面质量研究

钨铜复合材料以高导热率,LED芯片热匹配等特性,成为LED散热基体的重点开发对象,而钨铜箔片轧制表面高平整性是首要前提,研究高效可行的微观整平方法意义深远。本文采用电解抛光的方法对钨铜箔片(W90Cu10)进行多次重复正交试验。以硫酸-磷酸系作为电解液,通过对抛光后箔片宏观表面质量评定、反射率测量及SEM微观表面形貌分析,初步确定了W90Cu10电解抛光的最佳工艺参数,分析了抛光液及工艺参数对抛光质量的影响及钨铜箔片电解抛光机理。实验表明:在硫酸与磷酸体积比2∶7、温度为45～55℃、抛光时间4～6 min、电流密度15～25 A/dm2条件下电解抛光试样表面相对反射率高达90%以上,表面呈镜面光亮。     

表面处理对钛镍合金丝材力学性能影响研究

对经过不同表面处理的钛镍合金丝材的力学性能进行了对比分析。研究表明：与酸洗及机械抛光相比，电解抛光可有效改善钛镍丝材的力学性能，而经电镀工艺处理后的试样则易发生氢脆现象，从而显著降低材料的力学性能指标。     

航空用钛合金疲劳性能测试试样的残余应力测试技术

准确检测加工带来的残余应力，确保疲劳试样符合标准要求，对测定钛合金的疲劳性能至关重要。本文对目前常用的残余应力的测试分析技术进行了介绍，并对适合钛合金疲劳试样残余应力测试的技术进行了讨论。结果表明，X射线衍射法是目前最合适的钛合金疲劳试样残余应力测试方法。     

化学抛光在金相试验中的应用

化学抛光是继电解抛光之后应用于金相试样的制备。早在1911年就有电解抛光的专利,而化学抛光到五十年代才有大量的著作发表。由于化学抛光的优越性而得到了广泛应用,也引起了金相工作者的兴趣并成功应用于金相试验研究工作中,不断有专述发表。但是它的理论并不成熟,     

生物医用TLM钛合金的水热法表面改性

对Ti-25Nb-3Zr-2Sn-3Mo合金(TLM钛合金)进行水热处理,温度为100~200℃。X射线衍射、拉曼光谱、扫描电镜和X射线光电子能谱分析表明,TLM钛合金经140~200℃水热处理后,表面形成了由氧化钛和氧化铌纳米颗粒(尺寸80~100 nm)组成的、含有较多羟基的薄膜。140℃以上水热处理TLM试样的亲水性和表面能升高,表面能以极化分量为主。在无钙Hank’s平衡盐液中的动电位极化实验表明,水热处理TLM试样的耐蚀性高于抛光试样。水热处理有利于改善TLM钛合金的生物相容性。     

电解抛光金属表面的原理探索

电解抛光是一种电化学加工工艺，近年来被广泛的应用于抛光金属表面，效果较好。通过各种公式及物理化学理论，对该工艺的各个主要部分进行了阐述，并对现行工艺中的一些技术问题提出了独到见解。     

TA12A钛合金热处理过程中等轴和片层α相演变行为研究

对近α 型TA12A钛合金进行热处理实验,利用扫描电子显微镜(SEM)和电子背散射衍射(EBSD)技术对热处理后的微观组织进行观察,研究了两相区固溶温度和冷却速率对微观组织的影响.研究表明:TA12A钛合金在980和1000℃保温后冷却时,β相向α相转变,一方面可以使得等轴α相长大,另一方面也可析出片层α相.等轴α相长...     

金纳米粉末的制备与特性

应用超声辅助电解法制备金纳米粉末.电解液由柠檬酸三钠、硫酸钠组成;金箔作阳极,钛合金杆作阴极;钛合金杆作为超声波放大转换器与20kHz的超声波源相连接.由于超声波的空化效应,在阴极形成金聚集体将分散到电解液中,这样通过控制电流密度、超声波脉冲的周期和幅度就可以获得直径约为50nm左右的面心立方结构(fcc)的金纳米粉末.利用透射电镜(TEM)、X射线衍射(XRD)、X射线光电子谱,表征了金纳米粉末的结构、形貌及其化学组分.     

热喷涂涂层的制备

对热喷涂层金相试样制备进行了介绍 ,并对一些技术问题给予提示。     

Effect of flexibility of the femoral stem on bone-remodeling and fixation of the stem in a canine total hip arthroplasty model without cement

The purpose of this study was to compare, with regard to fixation of the implant and femoral bone resorption, two fully porous-coated stems of different stiffnesses in a canine total hip arthroplasty model. A bilateral arthroplasty was carried out with insertion of a titanium-alloy stem (which had stiffness properties comparable with those of the canine femur) on one side and with insertion of a composite stem (which was three to fivefold more flexible than the canine femur) on the contralateral side. Eight femora were evaluated at six months and eight, at eighteen months after the operation, to determine the extent of bone ingrowth, periprosthetic cortical area, intracortical porosity, and bone-remodeling. Despite the markedly greater flexibility of the composite stems, no significant difference could be detected (with the numbers available), with regard to the overall degree of femoral stress-shielding, cortical area, or cortical porosity, between these stems and the stiffer, titanium-alloy stems at either time-period. However, the composite stems had less bone ingrowth and more formation of radiopaque lines than did the titanium-alloy stems. At eighteen months, the values for bone ingrowth were 9.7 +/- 5.38 percent (mean and standard deviation) for the composite stems compared with 28.1 +/- 5.31 percent for the titanium-alloy stems (p = 0.003). Furthermore, the histological sections from the femora containing a composite stem showed radiopaque lines indicative of fibrous ingrowth approximately threefold more often than did those from the femora containing a titanium-alloy stem (p = 0.02).     

Effect of asthma treatment on urinary growth hormone excretion in children

We present a case report of extensive wear that occurred on the surface of the titanium-alloy head of a shoulder prosthesis after only 2 years' service. Such wear warrants discontinuing the use of titanium-alloy articulating surfaces even in nonweight-bearing joints.     

硬质合金金相试样制备方法的探讨

提出了硬质合金金相试样制备质量的基本要求，分析了现行制样方法中存在的问题，进行了一些改进和探索。笔者认为在制样方法改进方面组织难点攻关、经验交流、技术论证和成果推广等系列活动很有必要。     

粉末烧结内氧化Ag-CdO电触头的金相分析

介绍了粉末烧结内氧化银氧化锡电触头材料金相试样的制备、显微组织的观察和分析方法,并探讨了银铝合金粉末压坯烧结内氧化的过程。结果表明,金相分析方法是控制烧结内氧化工艺和产品质量的有效手段。     

粉末烧结内氧化Ag－CdO电触头的金相分析

介绍了粉末烧结内氧化银氧化锡电触头材料金相试样的制备、显微组织的观察和分析方法，并探讨了银铝合金粉末压坯烧结内氧化的过程。结果表明，金相分析方法是控制烧结内氧化工艺和产品质量的有效手段。     

Analysis of shear stress distribution in pushout process of fiber-reinforced ceramics

The interfacial shear stress distribution of a thin specimen of SiC fiber-reinforced glass matrix composite (fiber volume fraction of 0.1, 0.5 and 0.7) during a fiber pushout process was subjected to finite element analysis using a three concentric axisymmetrical model which consisted of fiber, matrix, and composite. A stress criterion was used to determine interface debonding. Effects of thermally-induced stress and a post debond sliding process at the interface were also included in the analysis. The analytical result showed that shear stress near the specimen surface was introduced during the specimen preparation process. Before the interfacial debonding, the distribution of shear stress during the pushout test was affected by the existence of thermally-induced stress in the specimen. The interfacial shear debonding initiated ≈ 30 μm below the pushing surface and the sliding at the debonded interface proceeded in the direction of both the pushing surface and back surface from the peak shear position; the debonding from the back surface initiated just before the complete debonding of the interface. The pushout load-displacement curve near the origin was straight, however, after the existence of interface sliding at the debonded interface, the curve exhibited non-linearity with the increase in applied load up to the complete debonding at the interface. This debonding process was essentially independent of the fiber volume fraction. The results indicate that the total of thermally-induced stress in the specimen and shear stress distribution generated by applied load are important for the initiation of debonding and the frictional sliding process of the thin specimen pushout test.     

X射线荧光光谱法测定煤灰成分

介绍利用X射线荧光光谱法测定煤灰成分的方法，讨论仪器的测量条件、试样制备条件的选择和合成标样的制备方法，并进行精密度与准确度试验，结果表明方法准确可靠。     

X射线荧光光谱法测定煤灰成分

介绍利用X射线荧光光谱法测定煤灰成分的方法，讨论仪器的测量条件、试样制备条件的选择和合成标样的制备方法，并进行精密度与准确度试验，结果表明方法准确可靠。