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91.
The effect of hydrogen heat treatment on impurity contents in aluminum nitride powder of different fineness is studied. Thermodynamic calculations are provided pointing to the possibility of forming gaseous hydrogen compounds with impurity elements. It is established that as a result of treatment the contents of impurity elements, i.e. oxygen, carbon, sulfur, are reduced by a factor of 3-13. The optimum hydrogen heat treatment regime is determined: a temperature of 1323 K and an exposure time of 30 min. 相似文献
92.
Capital cost correlations are given for oil-water separators, equalization basins, primary clarifiers, clarifiers and clarifier mechanisms, reverse osmosis unit, ultrafiltration units, gravity filters and miroscreens. Data are included for raw sewage, intermediate and recirculation pumping stations and for preliminary treatment (or bar screens, grit removal, overflow and bypass chamber and Parshall flume), for grit removal, comminution and gas stripping. The correlations are accurate to ± 30%, expressed in Canadian dollars and adjusted to a Marshall and Swift value of 1000. Details as to what components are included in the cost are given. Data are given for the labour and material costs to create a working process module. For inflation indices, a critique of the Engineering News Record, EPA small city, Marshall and Swift, Chemical Engineering and Southam inflation indices suggested that the Marshall and Swift index is most appropriate for the construction and process equipment studied here. Concerning the currency exchange, for the equipment and processes in this study, equipment costs the same whether expressed directly in US or Canadian dollars. To put the current data into perspective, several hundred sources of cost data were analyzed. The major correlations are compared, on a consistent basis, with current data. 相似文献
93.
文章概要论述了一种新型民用炸药-含过期火药粉状工业炸药在配方、制造工艺等方面所进行的实验研究。结果表明,该炸药性能良好、制造技术安全可靠,值得推广。 相似文献
94.
通过力学性能评估和金相组织观察,研究五种热处理制度,两个周期的试验结果,确定了K418B合金细晶铸造整体涡轮的真空热处理工艺。 相似文献
95.
The condition of the surfaces is of crucial importance for the deuterium permeation through materials. In this work a study of the surface constants for the adsorption (σk1) and release (σk2) of deuterium under different surface conditions on the martensitic steel DIN 1.4914 (MANET) has been carried out. The growth of an oxide surface layer (Cr2O3) of about 25–30 nm in a MANET sample, heat treated in an oxidizing environment, compared to the bare MANET that have a ‘natural' oxide of about 5 nm has provoked a reduction of both the permeation rate and the recombination coefficient (about 3 orders of magnitude). In addition, the permeation governing process has changed from diffusion-limited to surface-limited. The measurements of the permeation rate of deuterium were performed by a gas-phase permeation technique over the temperature range 574–746 K and for deuterium driving pressures in the range from 3 to 105 Pa. 相似文献
96.
时效处理对 TiNi 合金相变与性能的影响 总被引:2,自引:0,他引:2
通过用TEM等方法研究热处理制度(固溶处理、时效处理)对TiNi合金相变组织和性能的影响,找出了最佳热处理制度。结果表明,在450~500℃进行时效处理,Ti-50.8at%Ni的合金出现了大量的Ti3Ni4相,且恢复率最高。 相似文献
97.
98.
介绍了造成铁路油槽车底油收不尽的原因,一是节约意识差;二是设备设施陈旧或维护不够;三是操作不当。提出了增强节约意识,挖掘设备潜力,采用合理的吸油方法的对策。 相似文献
99.
100.
Chao M. Huang Dong Zhu Xu Yuren Waltraud M. Kriven Chao Y. Yuh 《Materials Science and Engineering: A》1996,220(1-2)
A composite of O′SiAlON (Si2-xAlxN2-xO1+x, with x 0.14) reinforced with 20 vol.% SiC monofilaments was fabricated by hot-pressing, at 1600°C, for 2 h under 34 MPa pressure. The mechanical and interfacial properties of the composites, as-fabricated as well as post-oxidized, were, investigated. The composite exhibited a significant improvement in ultimate flexure strength (640 MPa) and work of fracture (42 kJ m−2) compared with that (350 MPa and 1.8 kJ m−2, respectively) of the monolithic material. These mechanical properties were slightly increased after the composite was heat treated for 24 h in air at 1200 and 1300°C. However, the composite exhibited a significant degradation in ultimate strength, while the work of fracture (WOF) remained unchanged after exposure in air at temperatures beyond 1400°C. The as-fabricated composite revealed a low interfacial shear strength (6.2 MPa) and a frictional sliding stress (3.2 MPa). After the composite was oxidized at elevated temperatures, the interfacial bonding and sliding stresses were reduced to noticeable extents, resulting from the degradation of the carbon coating layer of the SiC monofilaments. 相似文献