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Liang Xu

Bio: Liang Xu is an academic researcher from Shanghai Jiao Tong University. The author has contributed to research in topics: Lubrication & Machinability. The author has an hindex of 2, co-authored 4 publications receiving 40 citations.

Papers
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Journal ArticleDOI
Qinglong An1, Chongyan Cai1, Fan Zou1, Liang Xu1, Ming Chen1 
TL;DR: In this article, the authors investigated the tool wear, surface topography, cutting torque, and surface profile in side milling Ti6Al4V under four sustainable conditions, i.e., dry, supercritical carbon dioxide (scCO2), scCO2 with antifreeze water based minimum quantity lubrication, and scCO 2 with oil-on-water based MQL conditions.

72 citations

Journal ArticleDOI
TL;DR: In this paper, the machinability of Ti-6Al-4V in finish milling process under four green cutting environments (CEs), i.e. dry, supercritical carbon dioxide (scCO2), supercritical CO2-based minimum quantity lubrication with water-based cutting fluid (sc CO 2-WMQL), and scCO2-OoWMQL CEs were investigated.
Abstract: Cryogenic environments are often adopted in machining difficult-to-cut materials such as Ti-6Al-4V alloy to control its cutting heat and improve machinability. This paper aims to study the machinability of Ti-6Al-4V in finish milling process under four green cutting environments (CEs), i.e. dry, supercritical carbon dioxide (scCO2), supercritical CO2-based minimum quantity lubrication with water-based cutting fluid (scCO2-WMQL), supercritical CO2-based minimum quantity lubrication with oil-on-water droplets cutting fluid (scCO2-OoWMQL). Peripheral finish-milling of Ti-6Al-4V was conducted under various cutting speeds, feed rates, radial depth of cut and CEs. The cutting force, cutting temperature, surface morphology and surface roughness were analysed. The experiment results show that the minimum cutting force and its coefficients, cutting temperature and surface roughness are obtained in scCO2-OoWMQL environment because of its excellent cooling/lubrication and chip evacuation performance, whereas the worst friction in the tool-workpiece interface leads to the worst performance under scCO2 CE. Additionally, the machined surface profile, cutting force and their spectrums under four CEs were studied. The fundamental frequency of machined surface profile is equal to that of cutting force envelope under dry and scCO2 CEs, which is also called beat frequency, therefore scCO2-WMQL and scCO2-OoWMQL CEs can improve the milling stability. The results indicate that scCO2-OoWMQL provides the best performance with regard to cutting force, cutting temperature, surface finish and clean production.

40 citations

Patent
14 Jan 2020
TL;DR: In this paper, the authors proposed a flexible numerical control machining clamp for beam edge strip parts, which can achieve high degree of automation degree and good flexibility, can achieve clamping and machining of bilaterally symmetrical beam edge strips parts of different sizes.
Abstract: The invention relates to a clamp for flexible numerical control machining. The clamp comprises a head positioning pin, a tail oil cylinder pushing mechanism and a first station clamp body and a secondstation clamp body, wherein the head positioning pin and the tail oil cylinder pushing mechanism are separately arranged at the two ends of a base, and the first station clamp body and the second station clamp body are arranged on the base. The first station clamp body and the second station clamp body are arranged on the base and matched with workpieces of different specifications; the head positioning pin and the tail oil cylinder pushing mechanism are used for positioning and clamping the workpieces in the length direction of a first station; and the tail oil cylinder pushing mechanism isused for clamping the workpieces in the length direction of the second station. The clamp has high degree of automation degree and good flexibility, can achieve clamping and machining of bilaterally symmetrical beam edge strip parts of different sizes, and also achieves high-efficiency and high-quality numerical control machining of the beam edge strip parts.
Patent
14 Jan 2020
TL;DR: In this article, an automatic turnover device for a numerical control machining clamp is presented. But the device is not suitable for turning over the beam flange strip parts of the machining process.
Abstract: The invention relates to an automatic turnover device for a numerical control machining clamp. The device comprises a servo motor, a speed reducer and a clamping turnover mechanism which are arrangedon a clamp base, wherein the servo motor is connected with the speed reducer through a coupler, the servo motor and the speed reducer are fixedly arranged on the base, the clamping turnover mechanismis fixedly connected with the speed reducer so as to realize 180-degree turnover of the clamping turnover mechanism, the clamping turnover mechanism comprises a hydraulic oil cylinder, a movable jaw,a fixed jaw, a sliding rail and a sliding block which are arranged in a shell, the hydraulic oil cylinder is connected with the shell and the movable jaw, the fixed jaw is connected with the shell, the sliding rail, the sliding block and the movable jaw are sequentially connected, and the sliding rail is arranged on the shell. According to the device, the automation degree is high, eudipleural beam flange strip parts with different sizes can be clamped and turned over, the machining efficiency is improved, and the automatic turnover among different stations of the beam flange strip parts is realized.

Cited by
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Journal ArticleDOI
TL;DR: In this paper , the cooling lubrication mechanism and technical iteration motivation of minimum quantity lubrication (MQL) were initially analyzed, and a quantized comparative assessment of cutting force, cutting temperature, tool wear, and surface quality under enhanced environmentally friendly lubrication turning, including parts enhanced by nanoparticles, cryogenic medium, ultrasonic vibration, and textured tools, was performed.

143 citations

Journal ArticleDOI
TL;DR: An extensive analysis of the literature on such cooling techniques as dry, conventional cooling system, minimum quantity of lubricant (MQL), minimum quantity cooling lubrication (MQCL), cryogenic lubrication, and high pressure cooling (HPC) is performed as mentioned in this paper.
Abstract: Products made of titanium and its alloys are widely used in modern areas like the mechanical engineering, instrument making, aerospace and medical sector. High strength and low thermal conductivity are the causes of difficulties with the machinability of these alloys. It is important to find ways to increase machinability by cutting titanium alloys. One way to implement this is to apply various methods of cooling on workpieces of titanium alloys and on cutting tools during machining. In this review article, an extensive analysis of the literature on such cooling techniques as dry, conventional cooling system, minimum quantity of lubricant (MQL), minimum quantity cooling lubrication (MQCL), cryogenic lubrication, and high-pressure cooling (HPC) is performed. The following groups of Ti alloys are considered: high-strength structural and high-temperature Ti alloys, intermetallic compounds, pure titanium, as well as composites CFRPs/Ti alloys. For the processes of turning, milling, drilling, and grinding, etc. it is shown how the type of cooling affects the surface integrity include surface roughness, tool wear, tool life, temperature, cutting forces, environmental aspects, etc. The main advantages, disadvantages and prospects of different cooling methods are also shown. The problems and future trends of these methods for the machining of Ti and its alloys are indicated.

140 citations

Journal ArticleDOI
TL;DR: In this article , a comprehensive review and critical assessment of the existing understanding of electrostatic atomization MQL is provided, which can be used by scientists to gain insights into the action mechanism, theoretical basis, machining performance, and development direction of this technology.
Abstract: Metal cutting fluids (MCFs) under flood conditions do not meet the urgent needs of reducing carbon emission. Biolubricant-based minimum quantity lubrication (MQL) is an effective alternative to flood lubrication. However, pneumatic atomization MQL has poor atomization properties, which is detrimental to occupational health. Therefore, electrostatic atomization MQL requires preliminary exploratory studies. However, systematic reviews are lacking in terms of capturing the current research status and development direction of this technology. This study aims to provide a comprehensive review and critical assessment of the existing understanding of electrostatic atomization MQL. This research can be used by scientists to gain insights into the action mechanism, theoretical basis, machining performance, and development direction of this technology. First, the critical equipment, eco-friendly atomization media (biolubricants), and empowering mechanisms of electrostatic atomization MQL are presented. Second, the advanced lubrication and heat transfer mechanisms of biolubricants are revealed by quantitatively comparing MQL with MCF-based wet machining. Third, the distinctive wetting and infiltration mechanisms of electrostatic atomization MQL, combined with its unique empowering mechanism and atomization method, are compared with those of pneumatic atomization MQL. Previous experiments have shown that electrostatic atomization MQL can reduce tool wear by 42.4% in metal cutting and improve the machined surface R a by 47% compared with pneumatic atomization MQL. Finally, future development directions, including the improvement of the coordination parameters and equipment integration aspects, are proposed.

102 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present surface integrity, tool wear characteristics and initiatives to improve them during the machining of hard-to-cut materials such as nickel, titanium and cobalt based.
Abstract: Today, superalloys (also known as hard-to-cut materials) such as nickel, titanium and cobalt based cover a wide range of areas in engineering applications. At the same time, challenging material properties namely high strength and low thermal conductivity cause low quality in terms of cutting tool life and surface integrity of the machined part. It is important to improve the machinability of this type of materials by applying various methods in the perspective of sustainability. Therefore, current study presents surface integrity, tool wear characteristics and initiatives to improve them during the machining of superalloys. In this manner, it is outlined the surface integrity characteristics containing surface defects, surface roughness, microstructure alterations and mechanical properties. Also, tool wear mechanisms for example abrasive, adhesive, oxidation, diffusion and plastic deformation are investigated in the light of literature review. Finally, possible improvement options for tool wear and surface integrity depend on machining parameters, tool modifications, cooling methods and trade-off strategies are highlighted. The paper can be a guide for the researchers and manufacturers in the area of sustainable machining of hard-to-cut materials as explaining the latest trends and requirements.

81 citations

Journal ArticleDOI
Qinglong An1, Chongyan Cai1, Fan Zou1, Liang Xu1, Ming Chen1 
TL;DR: In this article, the authors investigated the tool wear, surface topography, cutting torque, and surface profile in side milling Ti6Al4V under four sustainable conditions, i.e., dry, supercritical carbon dioxide (scCO2), scCO2 with antifreeze water based minimum quantity lubrication, and scCO 2 with oil-on-water based MQL conditions.

72 citations