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Indexed by:期刊论文
Date of Publication:2018-03-01
Journal:INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
Included Journals:SCIE、EI
Volume:95
Issue:5-8
Page Number:2783-2793
ISSN No.:0268-3768
Key Words:Ti-6Al-4Valloy; WC-co tool; Diffusion wear; Cryogenic cooling; Element affinity
Abstract:This paper presents the first comprehensive investigation on milling Ti-6Al-4V alloy in cryogenic cooling, and it mainly focuses on the effect of diffusion wear behavior of WC-Co tool in operations. Diffusion coefficient calculation model of elements is established considering cutting temperature. A series of conventional and cryogenic cooling experiments are conducted, as well as element diffusion behaviors are observed and analyzed by SEM and EDS, and the diffusion coefficient of model is verified. Similarly, the influence of cutting temperature on diffusion wear on contact surface of tool/workpiece is studied. Through the phase diagram analysis of elements, the affinity behaviors between them are researched, and then the mechanism of diffusion wear is deduced. The results showed that the calculation results of diffusion coefficient are similar with the measurement ones under two kinds of cooling model at 150 m/min speed, and they are close to diffusion effect of 1200 and 800 K, respectively. Moreover, Co element has the most difficult diffusion ability, but C and Ti are easiest. At cryogenic conditions, their diffusion degrees are all apparent decline compared with conventional one, and the cutting temperature rise is slow with the increase of cutting speed. Although the former cutting force increases, the workpiece rebound is well suppressed. Furthermore, the friction degree of tool/workpiece is decreased on contact surface, and the elements diffusion behavior of carbide tools is improved. In cryogenic cooling condition, decreased friction degree of tool/workpiece and the weakening of solid solution degree between Ti, W, and Co elements are the main reasons for effectively inhibit of the diffusion wear.
