Surface integrity of ultrasonic-assisted dry milling of SLM Ti6Al4V using polycrystalline diamond tool

Author(s):  
Yongsheng Su ◽  
Liang Li
Author(s):  
F J Ma ◽  
D M Guo ◽  
R K Kang ◽  
Y J Ren

It is usually hard to obtain a good surface quality of carbon/carbon (C/C) composite by turning due to its non-homogeneity and anisotropy. Contrasting experiments of ultrasonic assisted turning (UAT) and common turning (CT) of the C/C composite were carried out using a polycrystalline diamond tool. The cylindrical surface of the turning was classified into four typical types based on different fibre orientations. The influence of fibre distribution characteristics on surface roughness was analysed by measuring and comparing the roughness of these surfaces, and an evaluation method of surface quality for the C/C composite after turning was established. The results of UAT experiments on the C/C composite show that UAT could effectively reduce the machining defect. The roughness of typical surfaces 1 and 2 machined using UAT was about 20 per cent lower than that using CT.


2012 ◽  
Vol 516 ◽  
pp. 516-521
Author(s):  
Chung Chieh Cheng ◽  
Dong Yea Sheu

This study describes a novel process to drill small holes in brittle materials such as glass, silicon and ceramic using a self-elastic polycrystalline diamond (PCD) drilling tool. In order to improve the surface roughness and reduce crack of the small holes, a new type of self-elastic PCD drilling tool equipped with vibration absorbing materials inside the housing was developed to fabricate small holes in glass in this study. The self-elastic PCD drilling tools could absorb the mechanical force by the vibration absorbing materials while the PCD tool penetrates into the small holes. Compared to conventional PCD drilling tools, the experimental results show that high-quality small holes drilled in glass can be achieved with cracking as small as 0.02mm on the outlet surface using the self-elastic PCD drilling tool.


2008 ◽  
Vol 389-390 ◽  
pp. 350-355
Author(s):  
Takeshi Harada ◽  
Takuya Semba

A truing technique that can be used to shape the tip of an electroformed diamond tool into a hemisphere and flatten diamond grains on the tool working surface at the same level as the bond face was developed. A polycrystalline diamond disk whose top surface roughened by electrical discharge machining was partially flattened by grinding was used as a truer. Diamond grains on the tool working surface were successfully flattened along the hemispherical tool profile when the grains mesh size of #1000 was employed. In addition, a grinding test using glasslike carbon as a work material revealed that a surface roughness of less than 50 nm Rz could be obtained in both cases when moving the tool on contour and scanning paths.


Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1179 ◽  
Author(s):  
Rufeng Xu ◽  
Yongxin Zhou ◽  
Xun Li ◽  
Shenliang Yang ◽  
Kangning Han ◽  
...  

The GH4169 superalloy has high strength at high temperatures. Cooling conditions have a major impact on the machined surface integrity, which further affects the fatigue properties of specimens of the GH4169 superalloy. The influence of cooling conditions on the surface integrity of the GH4169 superalloy is first studied during the side milling. Then, the effect of surface integrity under different cooling conditions on the fatigue behavior of specimens of the GH4169 superalloy is investigated by a standard tensile and tensile–mode fatigue testing. The results obtained show that surface roughness and the depth of the plastic deformation layer in wet milling and dry milling makes little difference, the surface microhardness rate in dry milling is slightly lower than that in wet milling, the surface tensile residual stress in dry milling is significantly higher than that in wet milling, and the fatigue behavior in dry milling is only about 50% of that in wet milling. In addition, the crack initiation of specimens of the GH4169 superalloy utilizing wet milling is on the subsurface, while that from dry milling is on the surface. Thus, cooling conditions have an important impact on the fatigue behavior of specimens of the GH4169 superalloy, and micro defects in dry milling are the main factors of decreasing of fatigue behavior of specimens of the GH4169 superalloy.


Measurement ◽  
2020 ◽  
Vol 163 ◽  
pp. 108008 ◽  
Author(s):  
Mohammad Lotfi ◽  
Saeid Amini ◽  
Zahra Aghayar ◽  
Sayed Ali Sajjady ◽  
Ali Akhavan Farid

2012 ◽  
Vol 516 ◽  
pp. 437-442 ◽  
Author(s):  
Benjamin Bulla ◽  
Fritz Klocke ◽  
Olaf Dambon ◽  
Martin Hünten

Diamond turning of steel parts is conventionally not possible due to the high tool wear. However this process would enable several different applications with high economical innovative potential. One technology that enables the direct manufacturing of steel components with monocrystalline diamond is the ultrasonic assisted diamond turning process. This technology has been investigated over the years within the Fraunhofer IPT and is now commercialized by its spin-off company son-x. Surface roughness in the range of Ra < 5 nm can be achieved and the diamond tool wear is reduced by a factor of 100 or higher. In order to prove the industrial suitability of the process, two aspherical shapes and one large spherical geometry have been manufactured. The possible form accuracies and surface roughness values will be described in this paper, as well as the tool wear. The goal was to achieve optical surface roughness and a shape accuracy below 300 nm.


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