Machinability improvement of compacted graphite irons in milling process with supercritical CO2-based MQL

2021 ◽  
Vol 68 ◽  
pp. 154-168
Author(s):  
Luqiang Tu ◽  
Jie Chen ◽  
Qinglong An ◽  
Weiwei Ming ◽  
Jinyang Xu ◽  
...  
2020 ◽  
Vol 56 ◽  
pp. 63-74 ◽  
Author(s):  
L.R.R. da Silva ◽  
F.C.R. Souza ◽  
W.L. Guesser ◽  
M.J. Jackson ◽  
A.R. Machado

2021 ◽  
Vol 20 (2) ◽  
pp. 27
Author(s):  
L. R. R. Da Silva ◽  
A. R. Machado

In the search for more energy-efficient internal combustion engines, the automotive companies keep pushing the working temperatures and pressures of the engines, leading to more extreme working conditions and so the necessity of new materials. Among the most promising materials for the new generations of engines is the compacted graphite cast iron, which is more wear-resistant than aluminum and tougher than gray cast iron. However, this combination of properties also leads to decreased machinability, increasing production costs and, therefore, their market competitiveness. This paper evaluated the correlation of mechanical and metallurgical properties and the cutting power and surface roughness of three grades of compacted graphite cast iron with the cutting temperature in the end milling process under different two different feed rates and cutting speeds. This analysis showed that the temperatures near the cutting zone are closely correlated to the material's mechanical properties, machining power, and resulting roughness. These results indicate that thermographic images are a good indicator of the overall correlation between the changes in material properties and the most usual machinability output parameters. 


Author(s):  
Lucien F. Trueb

Crushed and statically compressed Madagascar graphite that was explosively shocked at 425 kb by means of a planar flyer-plate is characterized by a black zone extending for 2 to 3 nun below the impact plane of the driver. Beyond this point, the material assumes the normal gray color of graphite. The thickness of the black zone is identical with the distance taken by the relaxation wave to overtake the compression wave.The main mechanical characteristic of the black material is its great hardness; steel scalpels and razor blades are readily blunted during attempts to cut it. An average microhardness value of 95-3 DPHN was obtained with a 10 kg load. This figure is a minimum because the indentations were usually cracked; 14.8 DPHN was measured in the gray zone.


Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
YH Tsai ◽  
TJ Hsieh ◽  
MC Liao ◽  
PJ Lien ◽  
CC Sun ◽  
...  

2019 ◽  
Vol 2 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Jimmy Jimmy ◽  
Diah Indriani Widiputri ◽  
Paulus Gunawan

Eichhornia crassipes is well-known as water hyacinth. Water hyacinth grows rapidly in the nutrient-rich water and high light intensity places. The uncontrollable growth of water hyacinth has caused many negative impacts to the environment. For instance, interrupted water transport and decreased population of aquatic lives. The capacity of utilising water hyacinth is slower than water hyacinth growth and water hyacinth is still considered as a threat to theecosystem. This work was focused on the study of the pharmacological activity and heavy metal content of water hyacinth in Lake Cipondoh, Tangerang. Fresh water hyacinth was pre-treated through oven-drying and milling process. After that, each part of the plant was macerated by using multiple extraction method with 96% ethanol/water and three variations of sample-to-solvent ratios (1:30, 1:50, and 1:75 w/v). The result of the experiment showed thatwater hyacinth leaves produced an extract with lowest IC 50 (55.76 ± 6.73 ppm) compared toother parts. The most optimum solvent used to achieve this result was 96% ethanol/water (1:1 v/v). In order to obtain the lowest antioxidant activity, the sample to solvent ratio used was 1:50 and the heavy metal in the extract was very low. With this result, it was concluded that there is a promising opportunity to apply the water hyacinth growing in Lake Cipondoh, Tangerang as herbal medicine ingredient. Through this utilization, the overall number of water hyacinth in Indonesia can be reduced or at the least be controlled, so that the environmental problem caused by this plant can be minimized.


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