Diffusion of sputtered inconel 617 coatings in titanium

INCONEL 617 coatings 10-to 13-μm thick were radio frequency (RF) magnetron sputtered onto commercially pureα-titanium substrates and heat-treated at 800 °C for 2 hours. The resulting structures were examined in cross section by scanning electron microscopy (SEM) and analytical transmission electron microscopy (TEM). Scanning electron microscopy of polished and etched cross sections showed that the coating remained continuous, and as a result of inter-diffusion, a layer66-μn thick had formed below the coating. Examination of the coating near the free surface by TEM showed it contained both M₂₃C₆ and M₆C carbide precipitates, while several micron-thick layers containing intermetallic phases such as σ,γ′, and Ti₂Ni were found near the substrate. Kirkendall voids 75 to 300 Å in diameter were present near the original INCONEL 617/α-titanium interface. The microstructure further below that interface contained a thin layer of titanium martensite and Widmanstätten α + Ti₂Ni. No TiNi or TiNi₃ was found. The diffusivity of nickel and titanium was reduced several orders of magnitude and is attributed primarily to the formation of intermetallic compounds in the coating and substrate.     

含Si金刚石涂层的工艺研究

利用微波等离子体辅助化学气相沉积的方法,以H₂、CH₄和D₄(八甲基环四硅氧烷)为沉积先驱物,探索了一种在硬质合金基底上制备出含Si元素的金刚石涂层的新工艺.试图利用这种新的方法,进一步提高金刚石涂层对硬质合金基底的附着力.实验结果表明:当D₄的流量相对CH₄的流量较大时,得到球团状的胞状组织;只有当D₄和CH₄的流量相当的情况下,才能沉积出质量较好的金刚石涂层,同时又含有少量的Si使金刚石涂层的附着力较好.     

In vivo dissolution behavior of various RF magnetron sputtered Ca-P coatings

Apolipoprotein E (apoE), a protein produced by glial cells, is responsible for maintenance of the structural integrity of the microtubules within the axon of the neuron. The gene associated with apolipoprotein E, APOE, influences the construction and regeneration of the microtubules in an APOE allele-specific manner: APOE 2/2 may be neuroprotective, whereas APOE 4/4 may be neurodestructive. Thus, APOE appears to be one genetic factor that modifies the brain's response to insult, and therefore may modify the severity of neuropsychologic deficits. This article presents an overview of the genetic relation between APOE and neuropsychological function in Alzheimer disease and proposes a relation between APOE and recovery after head injury.     

Influence of alloy elements on the wear resistance of nickel-base detonation coatings

Translated from Poroshkovaya Metallurgiya, No. 9(321), pp. 46–48, September, 1989.     

电沉积Ni-W-WC复合镀层摩擦磨损性能

为了提高Ni-W合金镀层的硬度,改善其耐磨性,在镀层中添加WC颗粒作为硬质相,采用乙醇作为分散剂,利用超声波分散和机械搅拌相结合使WC颗粒均匀地分散于镀液中. 初步探究WC的添加量对镀层硬度及耐磨性能的影响. 结果表明:其他工艺条件不变的情况下,在一定范围内添加WC颗粒,可以较大幅度地提高镀层的硬度及耐磨性;WC添加量为1 g/L时,镀层的综合力学性能最好.      

Structure and wear resistance of molybdenum-base composite galvanoplasma coatings

Translated from Poroshkovaya Metallurgiya, No. 1(313), pp. 31–34, January, 1989.     

Si 元素对 CoCrAlY 涂层组织及性能的影响

在GH907基体上制备了三种不同Si含量的CoCrAlY合金涂层,对800℃涂层耐75%Na_2SO_4+25%NaCl熔盐腐蚀性能进行了测试分析,研究了1050℃下,Si元素对涂层抗氧化性能的影响,测定了不同Si含量涂层的抗热震性能。对实验条件下涂层的氧化产物、腐蚀产物及显微形貌进行了测定分析。研究结果表明:Si元素在高温下通过促使涂层表面Al_2O_3膜的形成提高涂层抗高温氧化及抗热盐腐蚀性能,但是过高的Si含量使涂层表面氧化膜破裂,使抗高温氧化性能下降。     

Dry sliding wear behavior of plasma-sprayed aluminum hybrid composite coatings

Al-SiC _p composite and Al-SiC _p -C _p hybrid composite coatings were produced by plasma spraying of premixed powders onto A356 alloy substrates. Four composite coatings, Al+20 vol pct SiC _p , Al+20 vol pct SiC _p +C _p , Al+40 vol pct SiC _p , and Al+40 vol pct SiC _p +C _p , were obtained. The dry sliding wear behavior of these coatings and pure aluminum have been studied at a sliding velocity of 1 m/s in the applied-load range of 25 to 150 N (corresponding to a normal stress of 0.5 to 3 MPa). The composite coatings had a significantly improved wear resistance over pure Al. The composite coatings with a higher SiC _p content of 40 vol pct exhibited superior wear resistance than those with a lower SiC _p content of 20 vol pct. The presence of graphite particles had different influences on the wear resistance, depending on the applied load. At lower loads, graphite improved the wear resistance considerably. At higher loads, the wear resistance of the hybrid composite coatings was similar to that of the composite coatings without graphite particles. At lower loads, an oxidative wear mechanism was dominant. At higher loads, delamination was a major wear mechanism. Graphite particles did not change their wear mechanism at the same applied loads.     

A comparative evaluation of the antifriction properties of plasma- and weld-deposited steel coatings

Conclusions The basic antifriction properties — running-in ability, minimum pressure to seizure, and the coefficient of friction of plasma-sprayed steel coatings are comparable to those of weld-deposited coatings and nodular iron. However, the wear resistance of such coatings is twice that of the former and three times that of the latter. The optimum plasma-deposition-process parameters, imparting high antifriction properties to coatings, are as follows: current intensity 425 A, voltage 30 V, rate of flow of plasma-forming gas 18 liters/min, rate of feed of wire 1.26 m/min, spraying range 50 mm, forced cooling.Translated from Poroshkovaya Metallurgiya, No. 9 (129), pp. 87–90, September, 1973.     

热处理对Fe基非晶合金涂层的相组成及摩擦磨损行为的影响

采用爆炸喷涂技术在Q235不锈钢基体上制备Fe基非晶合金涂层,在500~700℃下对涂层进行热处理,研究热处理温度对涂层的相组成和摩擦磨损性能的影响。结果表明:随热处理温度升高,涂层中非晶相含量明显减少,700℃热处理后,非晶相含量(体积分数)由热处理前的85.54%降至38.94%;热处理后涂层结构变得更致密;喷涂态涂层的平均显微硬度为1 095.6 HV0.05,500℃热处理后硬度变化不大,随热处理温度升高呈缓慢上升的趋势;与喷涂态涂层相比,500和600℃热处理后涂层的平均摩擦因数稍有增加,而700℃热处理后平均摩擦因数减小15%;热处理温度为600℃时涂层的磨损量较热处理前降低20%,耐磨性能最好,而热处理温度为700℃时涂层的质量磨损增大到热处理前的3倍以上,主要是涂层晶化相明显增加,氧化物含量增多,涂层变脆所致;磨损机制为则由喷漆态的粘着磨损向磨粒磨损,再到二者混合机制磨损转变。     

Structure and wear of detonation coatings made from eutectic iron-base powders

Conclusions Change of detonation spraying parameters substantially affects the structure and tribological properties of coatings made from iron-based eutectic-alloy powders containing refractory inclusion phases. This change permits the application of dense, wear-resistant coatings on low-carbon steels. The tribological properties of the friction pair, detonation eutectic coating versus U8 steel, are improved by changing the micromechanical properties of the coating structural constituents.Translated from Poroshkovaya Metallurgiya, No. 9(261), pp. 71–76, September, 1984.     

“双层金属布”硬质涂层耐磨性能的研究

对复合在钢基体上的WC-Ni-Fe-Co系“双层金属布”硬质涂层的相对耐磨系数ε进行了测定,对比耐磨件是HRC60的高速钢,实验采用磨粒磨损和摩擦磨损,实验结果表明WC-Ni-Fe-Co系“双层金属布”涂层耐磨性明显优于高速钢（HRC60）,涂层耐磨性主要与WC相含量有关。