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Promise of Self-lubricating Aluminum-Based Composite Material
Published in Chander Prakash, Sunpreet Singh, J. Paulo Davim, Functional and Smart Materials, 2020
Neeraj Kumar Bhoi, Harpreet Singh, Saurabh Pratap
In the applied area of the tribological component, most of the materials struggle between the different phenomenon of friction and wear process. However, this can be greatly minimized by the virtue of the lubricating medium between the mating surfaces. The lubricant material provides the shearing between the mating part that, in turn, reduces the friction coefficient and provides better sliding actions, which results in increased life to the component. The shear strength value of the lubricating layer is less than the mating part. Therefore, the lower value of the strength reduces the friction value. The major challenges arise when the material has to create an extreme work environment such as a vacuum, extremely low-temperature zone and extreme contact pressure area [6]. This situation can be eliminated by the use of self-lubricating material (SLM), which helps in reducing the friction between the contact area. The function of the SLM is similar to that of applied lubricating medium between the counterpart. SLM provides the low shear strength between the surface which in turn minimal friction between the mating parts. To enhance the better and more lubricity between the surfaces, the synergy of lubricating medium and SLM can be utilized. This process can have a better influence on the wear performance of the material.
A Morphological Process Model
Published in Leo Alting, Geoffrey Boothroyd, Manufacturing Engineering Processes, 2020
Leo Alting, Geoffrey Boothroyd
The basic process here is mechanical (fracture) and the medium of transfer is rigid. By varying the geometry of the medium of transfer (the tools/dies) and the pattern of motions, a number of different processes are obtained (see Fig. 1.30). These include blanking, punching, and shearing.
General introduction
Published in Adedeji B. Badiru, Handbook of Industrial and Systems Engineering, 2013
Sheet-metal operations include shearing, bending, stretch forming, spinning, and explosive forming. Shearing is usually the first operation performed in sheet-metal fabrication and can be categorized into blanking and piercing (punching). In the former operation, the slug cutout is important, whereas in the latter operation, the sheet from which the slug is cut is important. Sheet-metal forming utilizes progressive dies or compound dies such that multiple operations can be combined in producing a single component.
Influence of tool parameters on ultrasonic assisted drilling of GFRP composites
Published in Advanced Composite Materials, 2023
Yiwen Zhang, Tao Chen, Hongbo Li, Zhenyan Duan, Haotian Li
By comparing the morphology of the main cutting edge of the fresh tool and the tool after the first drilling, we can judge the wear of each tool. From (Table 4), we can clearly observe that the width of the main cutting edge of the HSS tool increases significantly after the first drilling process and there are many pits, which proves that the wear of the HSS tool is more serious at this time. Similarly, it is found that the width of the main cutting edge hardly increases by comparing the main cutting edges of carbide and PCD tools before and after machining, which indicates that the degree of wear is extremely small and basically negligible. In the main cutting edge of carbide and HSS tools, the burn caused by the high temperature of the drilling process can be clearly observed. However, for PCD drills such high temperature and corrosion-resistant tools do not show large changes after the drilling process. In order to explore the influence of worn tools on drilling machining, we conduct a second drilling experiment with the same parameters. From the thrust experimental results in Figure 10, it is found that the machining results of carbide tools and PCD tools do not fluctuate greatly when the tools are not obviously worn. However, the thrust increases by up to 27.6% during both machining processes for HSS tools that shows significant wear. The main cutting edge of fresh tool has a sharp radius of rounded corners, which makes the contact area between the main cutting edge of the tool and the surface to be machined smaller and stronger shear effect. The wear of the tool causes dulling and chipping of the main cutting edge, which reduces the shearing effect. Material removal relies more on the squeezing effect of the cutting edge, which eventually leads to an increase in thrust during the machining process. Furthermore, with the increase in cutting speed, the increase in thrust in two successive drillings also increases, which is mainly due to the increase in the number of cutting material per unit time of the cutting edge and tool friction intensifies causing rapid wear of the HSS drill edge. This is also the reason why most GFRP composite machining manufacturers do not use HSS tools for processing. In addition, it can be seen from Figure 10 that the change of thrust is small when the feedrate is kept constant at 0.1 mm/rev and the spindle speed is increased from 500 rpm to 3000 rpm, which also proves that the influence of spindle speed on the thrust of GFRP composites machining is low.