Papers by Keyword: Green Machining

Abstract: Advanced materials like nickel and titanium have unique combinations such as low thermal conductivity, high chemical reactivity, and high hardness. Machining these materials requires suitable lubricant and proper cooling technique for increasing tool life, decreasing cutting temperature, and improving surface roughness. This paper presents a brief review done on gas-based coolant-lubricants (CLs) used in the form of either gas or cooled-pressured air and gases. Main gas-based CLs are air, N₂, and CO₂. Investigations of previous researches include hypered cooled air (at different cooling temperatures), minimum quantity lubrication (MQL), and gases which have been used on machining operation that affect tool life and surface finish. Compresed N₂ and cooled air with MQL was identified as the most suitable coolant-lubricants for machining performance. Furthermore, this type of gas-based coolant-lubricant (CLs) is considered as one of the environmentally conscious machining.

Abstract: The machining process of titanium alloys always need special control by using coolant and lubricant as it is one of the difficult-to-cut materials. The cutting experiments are carried out based on green cooling and lubricating technology. To achieve green cutting of titanium alloy Ti-6Al-4V with water vapor cooling and lubricating, a minitype generator is developed. Compared to dry and wet cutting, the using of water vapor decreases the cutting force and the cutting temperature respectively; enhances the machined surface. And it can help to chip forming and breaking. Water vapor application also improves Ti-6Al-4V machinability. The excellent cooling and lubricating action of water vapor could be summarized that water molecule has polarity, small diameter and high speed, can be easily and rapidly to proceed adsorption in the cutting zone. The results indicate that the using of water vapor has the potential to attain the green cutting of titanium alloy.

Abstract: The growing interesting in the use of silicon carbide in automotive components, biomaterials, energy, among others, which demand the production of parts with complex geometry that are difficult to obtain by conventional compaction techniques, motivates the search for developing new conformation processes. Within this context, this paper investigates the production of pieces of silicon carbide through the gelcasting process and subsequent green machining of these parts. Three systems of monomers were studied: MAM-NVP-MBAM, MAM-PEG (DMA) and MAM-HMAM. The effect of the concentration of monomers, concentration of chemical initiator and the ratio of chain-forming and crosslinker monomers on the cutting force during machining and surface roughness were evaluated. These data are compared with values of flexural strength and hardness of samples produced under the same conditions. Through a statistical analysis it was determined the best formulation for the production of parts of SiC with favorable characteristics of green machining.

Abstract: Since Green Manufacturing has been becoming the future trend of the manufacturing industries, metal cutting companies are being compelled to reduce their impact on the environment as more international and government environmental protection legislation is introduced. As an important component of Green Manufacturing, Green Machining has been proposed as a new conception and agreed by more and more people. To realize Green Machining, some suggestions are given and some effective methods or technologies are briefly introduced in this paper from two perspectives of reducing environmental pollution and saving natural resources. By comparing these technologies, it is found that the hybrid processing technologies, MQL and Water jet machining are relatively easy to implement.

Abstract: Gear hobbing in cryogenic air with minimal quantity lubricant (MQL) is a better choice to take place of traditional gear hobbing in oily cutting fluid, in which cryogenic air with pulverized vegetable oil place the great amount of mineral cooling oil, to play the role of lubrication, cooling, chip clearance, and rust prevention. By the comparative experiments, differences on cutter wear are explored, among cryogenic gear hobbing with MQL, gear hobbing in oily cutting fluid, and dry gear hobbing. It indicates that the gear hobbing in cryogenic air with minimal quantity lubricant is practical, and not only a great amount of cooling oil is saved to lower cost and environment pollution, but also life-saving of hobbing cutter reduces production cost.

Abstract: From the perspective of clean production process, this paper summarizes the present research status of green cooling machining at home and abroad and analyzes the problems of coolant cooling during machining metal materials in traditional method and. The green cutting process tests using water vapor for cooling lubricant were done and the single-factor method was used. The cutting tests for the high-temperature alloy GH4169, titanium alloy TC4 and stainless steel Cr12 were done by the carbide cutting toolsunder th condition of distilled water, emulsion, water vapor for cooling lubricant and dry cutting. These tests results showed that in same process parameters, main cutting force Fc can be reduced by about 30%, 26% and 22% respectively when using water vapor for cooling lubricant than using dry cutting, distilled water and emulsion, while the cutting temperature T can be decreased by about 12%, 6% and 3% respectively.

Abstract: Due to environmental concerns and the coming legislations, pollution-free and eco-friendly minimum quantity lubrication (MQL) technology has become focus of attention in manufacture field. The MQL and cooling system in this work has been designed, fabricated and used. The cutting performance of MQL with cooling air compare with the conventional cooling method in milling of GH4169 aerospace superalloy is evaluated based on analysis of cutting force and surface finish. The effect of cutting parameters (depth of cut, feed rate) on machining performances is analyzed. The experimental results show that, the application of MQL and cooling air brings about a lower cutting force, better surface finish compared to conventional coolant environment.

Abstract: The machining process of titanium alloys always need special control by using coolant and lubricant as it is one of the difficult-to-cut materials. To achieve green cutting of titanium alloy Ti-6Al-4V with water vapor cooling and lubricating, a minitype generator is developed. Compared to dry and wet cutting, the using of water vapor decreases the cutting force and the cutting temperature respectively; enhances the machined surface appearance. Water vapor application also improves Ti-6Al-4V machinability. The excellent cooling and lubricating action of water vapor could be summarized that water molecule has polarity, small diameter and high speed, can be easily and rapidly to proceed adsorption in the cutting zone. The results indicate that the using of water vapor has the potential to attain the green cutting of titanium alloy instead of cutting floods.

Abstract: According to the characteristics and cutting requirements of the compressor impeller, such as low rigidity, easy to produce deformation and vibration in machining process, the high speed machining technology was adopted to reduce time, the virtual manufacturing technology was used to solve processing problems in computer before the trial machining and improved programming speed and other key supporting technologies were adopted. The study shows that this green processing of impeller had high machining efficiency, good surface roughness and product quality, low production cost and light environmental pollution. It accords with modern green machining development trend.

Abstract: In this paper, the green RBSC was prepared by gel casting process. The influences of the monomer content (MBAM and AM) and monomer ratio (MBAM to AM) on the flexural strength were investigated. The results indicated the flexural strength of green body was up to 8MPa and the micro- structures were homogeneous. The green RBSC bodies were machined by CNC grinding machine with diamond-coated grinding tools. Machining tests showed the green component could be machined without appended defects. It was found that green machining as a ‘top-down’ approach was a potential alternative for the rapid fabrication of complex-shaped ceramics, especially for some one-of-a-kind products.