Carbonitriding at 700°C with subsequent hardening of the surface layer

Conclusion Carbonitriding at 700°C in a mixture of 70–30% of ammonia and 30–70% of endogas (or natural gas) is recommended for the production of a diffusion layer with a good set of operational properties (for example, with high wear resistance).Moreover, the use of a gaseous atmosphere based on commercial nitrogen (50–90%) with ammonia, natural-gas, oxygen, or carbon dioxide additives is promising for carbonitriding at 700°C. Here, this medium should not contain more 0.5–1.0% of O₂ and 3% of CO₂. The nitrogen-based gaseous atmospheres ensure the attainment of quality diffusion layers with decreased risk of explosion and saving of energy resources.Moscow Automobile Traffic and Highway Construction Institute. Nongovernmental Production Union "All-Union Scientific-Research and Experimental Design Institute for Trade Machine Construction. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 32–36, May, 1987.     

Superconductivity effects near the metal-insulator transition in granular indium films

The paper reports on an investigation of the electric resistance as a function of temperatureT, magnetic fieldH, and applied voltageV in granular indium films when approaching the metal-insulator transition (MIT) due to increased thickness of the oxide layers between granules. The dependences are shown to be governed atT5 K by competition of the hopping conductivity and the Josephson tunneling of electrons, sometimes giving rise to a resistance minimum inR(T) associated with superconductivity. It was also found that even when the intergranular Josephson tunneling is totally suppressed, transition of granules to the superconducting state influences essentially the dependencesR(T, H), changing the functional form ofR(T) and resulting in anomalously high negative magnetoresistance. This is shown to stem from the change of the character of activated electron tunneling as the granules become superconducting.     

塑性加工方法在粉末高温合金中的探索研究

采用塑性加工方法,本文初步探索了预变形对PREP高温合金粉末及热等静压后合金显微组织的影响.结果表明,粉末预变形可以促进热处理后粉末组织的均匀化,并可降低合金的再结晶温度,改善合金组织,消除部分枝晶,对提高粉末的利用率及降低粉末高温合金盘件的成本具有较大的实际意义.     

纳米晶镁铝尖晶石透明微晶玻璃的晶化行为研究

利用DTA、XRD和TEM研究了制备工艺对微晶玻璃晶化行为的影响，并制备出具有纳米镁铝尖晶石为晶相的微晶玻璃。     

NH4SCN从ROH-CTMAB-C12H26载金有机相中反萃金

研究了硫氰酸铵（NH4SCN）从混合醇（ROH）－十六烷基三甲基溴化铵（CTMAB）－正十二烷（C12H26）载金有机相中反萃金，考察了平衡时间，PH值，反萃剂浓度，温度等因素对反萃率的影响及有机相的循环使用，绘制了反萃等温曲线，结果表明，NH4SCN对金具有较高反萃率，可顺利实现金的反萃。     

新型气动溢流阀及其动态特性的仿真分析

本文在介绍一种新型气动溢流阀的基础上,运用计算机仿真技术研究该阀的动态特性,建立了气动溢流阀的基本动态微分方程,采用数值方法求解方程,并把仿真结果用于指导气动溢流阀的设计,得到了满意的效果。     

利用“球化效应”激光扫描制备球形Ti粉的研究

利用“球化效应”，在SLS设备上探索将异形Ti粉转化为高性能球形粉末的可行途径。通过系统地改变激光功率、扫描速度，以及选取合适的激光扫描间距，探明了形成“球化效应”的工艺条件，并在激光功率为600W，扫描速度为30mm／s时，获得了较为理想的球形Ti粉。通过对球化过程进行理论分析，得出了选取激光扫描制备球形Ti粉工艺参数的准则。     

高纯钨中杂质元素的化学光谱法测定

采用以一定比例的ＨＮＯ３和ＨＣｌ为介质，使钨沉淀成钨酸与杂质分离，然后用碳粉吸附杂质再进行光谱测定的方法，对高纯钨（包括金属钨、三氧化钨、钨酸、钨酸铵）中１５个杂质元素Ｆｅ、Ｎｉ、Ｃｕ、Ｍｎ、Ａｌ、Ｖ、Ｃｒ、Ｃｏ、Ｃａ、Ｍｓ、Ｐｂ、Ｓｎ、Ｂｉ、Ｃｄ、Ｂｅ进行了测定，取得了理想的结果，测定下限可达（０．１～０．５）×１０（－６）。     

SERT结晶器液位控制系统

介绍一种梅山冶金公司板坯连同上应用的新型的结晶器液位控制系统，它由浮式式液位检测装置，ＲＳＥ１０００控制器和电动塞棒执行机构所组成，由法国ＳＥＲＴ公司成套制造。