Grinding of flat glass with Fe- and Cu-based diamond tools

Author(s):  
Sabri Ozturk

Preparation of grinding wheels is the most important effective factor in glass machining. This article presents the comparison of the iron- and copper-based grinding tools. The performance of the tools is investigated based on technical and commercial aspects using same cutting speeds, feeds, and sizes of diamond grits. Scanning electron microscope is used in order to observe the microstructures of cutting tools. The service life of the grinding tools is determined on the production line in a flat glass plant. A lifetime of Fe-based diamond tools is longer compared to the copper-based wheels. The impact of metal bond materials on the service life is examined. The results show that the Fe-based tools are more economical and more useful for grinding of glass. The holding of Fe-based bonding to diamond grit is stronger than the copper-based ones.

2021 ◽  
Vol 11 (21) ◽  
pp. 10236
Author(s):  
Lingfeng Xu ◽  
Zhanhua Song ◽  
Mingxiang Li ◽  
Fade Li ◽  
Jing Guo ◽  
...  

The working environment of agricultural cutting tools is poor, and the operational quality and efficiency are reduced after they become blunt. This study aimed to develop a high wear-resistant agriculture knife with a long life. A Ni–WC alloy, wear-resistant layer was prepared using laser cladding technology on one side of the cutting edge of a 65 Mn silage knife. A self-grinding edge was formed when the cladded knife was used, which improved the cutting quality and service life of the knife. The microstructure, phase, composition, and hardness distribution of the cladding layer were detected and analyzed. The impact toughness and wear resistance of the laser-cladded samples were analyzed, and the cladded knife was tested in the field. The results show that a cladded layer with a dense microstructure formed metallurgical bonds with the substrate. The microhardness was uniform across the cladded layer, and the average hardness of the micro Vickers was approximately 1000 HV(0.2), which was approximately three times the hardness of the substrate. The impact toughness and wear resistance of the coated knife were obviously higher than those of uncoated knives. The field tests showed that compared with a conventional 65 Mn knife, the self-grinding knife with laser cladding could maintain its sharp cutting shape after operation for 76 h, which greatly extended the service life of the knife. This study improved the service life of an agricultural cutting tool, which enhanced the cutting performance and efficiency at the same time.


2007 ◽  
Vol 534-536 ◽  
pp. 1101-1104 ◽  
Author(s):  
James C. Sung

Although diamond tools have been used for over a century, the diamond grits distribution in the matrix is not uniform. This is because the large and light diamond grits tend to segregate from the small and heavy metal powder during the mixing process, hence diamond distribution in the diamond tools is intrinsically heterogeneous. As a result, the cutting performance of the diamond tools cannot be optimized. In 1997, Dr. James Chien-Min Sung applied two historical patents that can allow the design of diamond distribution according to a predetermined pattern. As the result, the life of diamond tools may be doubled; and the cutting speed, may also be twice as high. The three-dimensional saw segments with arrayed diamond grits were made back in 1999 with the improved performance as predicted. The Sung invention can allow the diamond tools industry to make ideal saw segment that has variable diamond size and diamond separation at different regions. Conventional diamond saws contain diamond grits that are distributed randomly in a metal matrix, as a result, their cutting speeds are slow and their sawing lives are short. In 1997, Dr. James C. Sung applied new patents that revealed revolutionary technology for making diamond tools with diamond grits set in a predetermined pattern. The diamond placement design was first appeared in a series of DiaGrid® products, such as wire saws and grinding wheels. In 1999, DiaGrid® pad conditioners was introduced and it has since become the world's standard for dressing pads, particularly those used for chemical mechanical planarization of semiconductor devices. In 2005, Shinhan adapted the idea and produced saw segments with diamond grits set in a predetermined pattern, their results confirmed that the sawing speed and the life were significantly improved over conventional designs.


Alloy Digest ◽  
1978 ◽  
Vol 27 (12) ◽  

Abstract STORA ASP 60 is a molybdenum-tungsten high-speed steel with high percentages of carbon, cobalt and vanadium. It is a powder metallurgy steel, has high hardenability and can be hardened by cooling in air or oil from the austenitizing temperature. It has an excellent combination of wear resistance, toughness, hot hardness and resistance to tempering. It is recommended for cutting tools for hard-to-machine material and high cutting speeds. This datasheet provides information on composition, physical properties, microstructure, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-342. Producer or source: Stora Kopparberg, Special Steels Division.


Alloy Digest ◽  
1978 ◽  
Vol 27 (9) ◽  

Abstract STORA ASP 30 is a high hardenability tungsten-molybdenum alloyed high-speed steel with high cobalt content. It is recommended for cutting tools for hard-to-machine material and high cutting speeds. It has excellent wear resistance, toughness, hot hardness and resistance to tempering. The excellent size stability and good grindability of ASP 30 make it very suitable for tools with a complicated shape. This datasheet provides information on composition, physical properties, microstructure, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-338. Producer or source: Stora Kopparberg, Special Steels Division.


Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.


2009 ◽  
Vol 416 ◽  
pp. 234-237
Author(s):  
Zhong Ming Cui ◽  
Peng Hui Deng ◽  
Lei Du

The dressing processes are conducted on the diamond grinding wheels using the rotary diamond tools and compared between the single point diamond dresser and the rotary diamond dressing tool in the following aspects, including the dressing force, tool wearing, dressing efficiency. The result shows that, the dressing performance of the rotary diamond tools is remarkable better than that of the conventional dressing method.


Author(s):  
Sandro Turchetta ◽  
Luca Sorrentino ◽  
Gianluca Parodo

Diamond tools suitable for machining operations of natural stones can be divided into two groups: cutting tools, including blades, the circular blades and the wires, and the surface machining ones, involving mills and grinders, that can be of different shapes. For the stone sawing process, the most adopted tool type is the diamond mill, whose duration and performance are influenced by various elements such as: the mineralogical characteristics of the material to be machined; the working conditions such as the depth of cut, the feed rate and the spindle speed; the production process of the diamond segment and the characteristics of both the matrix and the diamond, such as the size, the type and the concentration of the diamonds and the metal bond formulation hardness. This work allows to indirectly assess the wear of sintered diamond tools by signal analysis (in time and frequency domain) of the cutting force components acquired in the process. The results obtained represent a fundamental step for the development of a sensory supervision system capable of assessing the tool wear and hence to modify the process parameters in process, in order to optimize cutting performance and tool life.


Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 287 ◽  
Author(s):  
Marina Volosova ◽  
Sergey Grigoriev ◽  
Alexander Metel ◽  
Alexander Shein

The main problem with ceramics used in cutting tools is related to the unpredictable failures caused by the brittle fracturing of ceramic inserts, which is critical for the intermittent milling of cyclic loading. A 125-mm-diameter eight-toothed end mill, with a mechanical fastening of ceramic inserts, was used as a cutting tool for milling hardened steel (102Cr6). For the experiments, square inserts of the Al2O3 + SiC ceramic were used and compared with the samples made of Al2O3 + TiC to confirm the obtained results. The samples were coated with diamond-like coating (DLC), TiZrN, and TiCrAlN coatings, and their bending strength and adhesion were investigated. Investigations into the friction coefficient of the samples and operational tests were also carried out. The effect of smoothing the microroughness and surface defects in comparison with uncoated inserts, which are characteristic of the abrasive processing of ceramics, was investigated and analyzed. The process developed by the authors of the coating process allows for the cleaning and activation of the surface of ceramic inserts using high-energy gas atoms. The impact of these particles on the cutting edge of the insert ensures its sharpening and reduces the radius of curvature of its cutting edges.


2013 ◽  
Vol 409-410 ◽  
pp. 381-387
Author(s):  
Binyad Maruf Abdulkadir Khaznadar

Privacy is one of the socio-cultural factors that affect on the formation of vernacular houses forms as a space organization and forms of elevations. Dealing with privacy varies from one culture to another, and this explains the diversity of houses forms in detached geographic regions. Privacy affects on the vernacular forms through a set of sub-factors. The most effective sub-factor on the elevations of traditional houses forms in Erbil city is the privacy of view between public and private spaces. In the selected samples this relationship is a direct one. The sub-factor of view privacy affects on the elevation form through form of the element and the position of the element regarding the whole elevation. Privacy is an effective factor that affects on the formal language of elevations in the traditional vernacular houses within the culture of Erbil city.


2020 ◽  
Vol 5 (9) ◽  
pp. 77
Author(s):  
Cláudia Ferreira ◽  
Ana Silva ◽  
Jorge de Brito ◽  
Ilídio S. Dias ◽  
Inês Flores-Colen

Existing maintenance policies have several limitations, mainly due to the lack of knowledge regarding the durability and performance of buildings. Usually, the maintenance policies are insufficiently accurate, neglecting the risk of failure over time and the global costs associated with repairs. In this study, a condition-based maintenance model, based on Petri nets, is proposed to evaluate the impact of three maintenance strategies of ceramic claddings in pitched roofs (CCPR): MS1—only total replacement; MS2—composed of total replacement and minor intervention and MS3—composed of total replacement, minor intervention and cleaning operations. In this study, 146 CCPR were inspected in situ, with a total area of 43,991.6 m2. The remaining service life of the CCPR; the global costs over the claddings’ lifetime (considering inspection, maintenance, replacement and disposal costs); the claddings’ degradation condition and the number of replacements during the time horizon are used to evaluate the performance of the different maintenance strategies through a simplified multi-criteria analysis. The results show that the gains in performance, in terms of expected service life and durability, of the consideration of preventive maintenance actions (minor interventions or cleaning operations) outweigh the increase of the operation costs.


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