共查询到20条相似文献,搜索用时 62 毫秒
1.
钛表面耐磨处理技术 总被引:2,自引:1,他引:1
钛是活性金属,与其它金属相比,钛的密度小,强度高,耐蚀性好,但由于其导热系数低,耐磨性差,摩擦时易产生烧接,为此,人们开始研究钛表面的硬化技术,以提高其耐磨性。钛的表面硬化技术通常有湿法电镀、渗碳、放电加工、PVD、CVD、气体氮化、堆焊等。 对钛进行表面硬化处理要考虑:①可高速处理,批量化生产;②成本低,可以大面积处理;③可以处理复杂形状的工件;④处理温度低;⑤硬化层的厚度适当。文中介绍3种较为理想的处理方法。1 KENI COAT技术KENI COAT(Kobe Excellent New Ideal Coat)是日本神户制钢所在成膜速… 相似文献
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
通过对淬火温度、自回火温度和贝氏体等温转变时间对大直径锻造钢球的硬度、冲击韧性以及组织的影响的研究,对比分析了不同热处理工艺的微观组织和性能的关系.研究结果表明:锻后空冷利用余热淬火时,较优淬火温度为750℃;淬火后自回火温度较高时,钢球芯部马氏体/下贝氏体复相组织中贝氏体组织含量较高且硬度较低,为了保证淬火后钢球具有高硬度及自回火的过程,则较优自回火温度为160℃;随着贝氏体等温转变时间的延长,贝氏体含量及冲击韧性显著提高,当贝氏体等温转变时间超过110 s时,硬度明显降低,即贝氏体较优等温转变时间为110 s.与常规淬回火相比,可得到钢球组织和性能的较优匹配,综合性能优于淬回火处理. 相似文献
15.
对二氧化钛颗粒无机表面处理的作用、过程、方法、理论和影响因素等方面进行了综合评述,阐述了硅、铝、锆包覆二氧化钛的原理,包覆工艺条件及其理论分析,展望了今后二氧化钛无机表面处理的研究方向。 相似文献
16.
17.
18.
N. N. Sereda M. S. Koval'chenko I. T. Belik V. G. Solomenko V. V. Uvarov V. V. Fedoseev 《Powder Metallurgy and Metal Ceramics》1977,16(5):394-397
Conclusions Grade KTS alloys can be used as wear-resistant materials and as tool alloys for machining unhardened steels.Translated from Poroshkovaya Metallurgiya, No. 5(173), pp. 94–97, May, 1977. 相似文献
19.
V. E. Kormyshev Yu. F. Ivanov V. E. Gromov S. V. Konovalov A. D. Teresov 《Steel in Translation》2017,47(4):245-249
The nanohardness, Young’s modulus, and defect substructure of the metal layer applied to Hardox 450 low-carbon martensitic steel by high-carbon powder wire (diameter 1.6 mm) of different chemical composition (containing elements such as vanadium, chromium, niobium, tungsten, manganese, silicon, nickel, and boron) and then twice irradiated by a pulsed electron beam are studied, so as to determine the correct choice of wear-resistant coatings for specific operating conditions and subsequent electron-beam treatment. The metal layer is applied to the steel surface in protective gas containing 98% Ar and 2% CO2, with a welding current of 250–300 A and an arc voltage of 30–35 V. The applied metal is modified by the application of an intense electron beam, which induces melting and rapid solidification. The load on the indenter is 50 mN. The nanohardness and Young’s modulus are determined at 30 arbitrarily selected points of the modified surface. The defect structure of the applied metal surface after electron-beam treatment is studied by means of a scanning electron microscope. The nanohardness and Young’s modulus of the applied metal after electron-beam treatment markedly exceed those of the base. The increase is greatest when using powder wire that contains 4.5% B. A system of microcracks is formed at the surface of the layer applied by means of powder wire that contains 4.5% B and then subjected to an intense pulsed electron beam. No microcracks are observed at the surface of layers applied by means of boron-free powder wire after intense pulsed electron-beam treatment. The boron present increases the brittleness. The increase in strength of the applied layer after electron-beam treatment is due to the formation of a structure in which the crystallites (in the size range from tenths of a micron to a few microns) contain inclusions of secondary phases (borides, carbides, carboborides). The considerable spread observed in the nanohardness and Young’s modulus is evidently due to the nonuniform distribution of strengthening phases. 相似文献