Verschleißmechanismen von CBN-Körnern/Wear mechanisms of CBN grains – Studies to identify and quantify CBN grain wear mechanisms

2021 ◽  
Vol 111 (01-02) ◽  
pp. 77-81 ◽  
Author(s):  
Thomas Bergs ◽  
Marc Bredthauer ◽  
Patrick Mattfeld ◽  
Sebastian Barth

Dieser Beitrag stellt die Ergebnisse von Verschleißuntersuchungen beim Einkornritzen mit CBN-Körnern dar. Der Fokus der Forschungsarbeit liegt auf der Identifizierung und Quantifizierung der Verschleißmechanismen in Abhängigkeit von den Prozesseinstellgrößen und den Korneigenschaften. Es werden charakteristische Phasen der Verschleißentwicklung identifiziert, die eine Zuordnung der Verschleißmechanismen Mikrobruch, Makrobruch und Abrasion zulassen.   The content of the paper is the presentation of the results of wear investigations on CBN grains used in single grain scratching. The focus of the research work is on the identification and quantification of the wear mechanisms as a function of the process parameters and the grain properties. Characteristic phases of wear development were identified, which allow an allocation of the wear mechanisms micro fracture, macro fracture and abrasion.

2017 ◽  
Vol 62 (3) ◽  
pp. 1803-1812 ◽  
Author(s):  
K. Shunmugesh ◽  
K. Panneerselvam

AbstractCarbon Fiber Reinforced Polymer (CFRP) is the most preferred composite material due to its high strength, high modulus, corrosion resistance and rigidity and which has wide applications in aerospace engineering, automobile sector, sports instrumentation, light trucks, airframes. This paper is an attempt to carry out drilling experiments as per Taguchi’s L27(313) orthogonal array on CFRP under dry condition with three different drill bit type (HSS, TiAlN and TiN). In this research work Response Surface Analysis (RSA) is used to correlate the effect of process parameters (cutting speed and feed rate) on thrust force, torque, vibration and surface roughness. This paper also focuses on determining the optimum combination of input process parameter and the drill bit type that produces quality holes in CFRP composite laminate using Multi-objective Taguchi technique and TOPSIS. The percentage of contribution, influence of process parameters and adequacy of the second order regression model is carried out by analysis of variance (ANOVA). The results of experimental investigation demonstrates that feed rate is the pre-dominate factor which affects the response variables.


2020 ◽  
Vol 44 (4) ◽  
pp. 295-300
Author(s):  
Sanjay Kumar ◽  
Ashish Kumar Srivastava ◽  
Rakesh Kumar Singh

Friction stir processing is an avant-garde technique of producing new surface composite or changing the different properties of a material through intense, solid-state localized material plastic deformation. This change in properties depends upon the deformation formed by inserting a non-consumable revolving tool into the workpiece and travels laterally through the workpiece. This research work highlights the effect of process parameters on mechanical properties of fabricated surface composites by friction stir processing. By using various reinforcing materials like Ti, SiC, B4C, Al2O3 with waste elements like waste eggshells, rice husks, coconut shell and coir will be used to fabricate the green composites which are environmentally friendly and reduces the problem of decomposition. The parameter for this experiment is considered as the reinforcing materials, tool rotation speed and tool tilt angle. The SiC/Al2O3/Ti along with eggshell are selected asreinforcement materials. The main effect of the reinforcement is to improve mechanical properties, like hardness, impact strength and strength. The results revealed that the process parameters significantly affect the mechanical properties of friction stir processed surface composites.


2021 ◽  
Vol 22 (2) ◽  
pp. 252-263
Author(s):  
Abdul Karim Shah ◽  
Ghulam Abbas Kandhro ◽  
Aqeel Ahmed Shah ◽  
Syed Nizam Uddin Shah Bukhari ◽  
Arshad Iqbal ◽  
...  

The cyclisation of citronellal to isopulegol is a significant intermediate stage in the production of menthols. In this research work, the effects of acid treatment on montmorillonite clay have been investigated and used in citronellal cyclisation reactions. Furthermore, the effects of acid treatment and hetero-poly acid impregnation have been determined on the textural and catalytic properties of montmorillonite clay. The designed catalysts were characterized by XRD, N2 sorption, and NH3- TPD techniques. Acid treatment of montmorillonite resulted in the enhancement of surface area and pore volume. The catalytic activity and selectivity parameters were lessened due to the severe leaching of Al ions from tetrahedral crystalline structures (e.g., weakened structure and loss of acidity). Among all prepared materials, the heteropoly acid supported HCl treated montmorillonite catalyst was observed as a more active, stable, and selective catalyst that showed the highest catalytic performance in citronellal cyclisation under optimized process parameters. The catalytic activity and selectivity were enhanced with rising mesoporosity and acidity parameters due to HCl acid treatment and HPA impregnation.


2019 ◽  
Vol 2 (4) ◽  
pp. 87 ◽  
Author(s):  
Isa Doverbratt ◽  
Helena Alexanderson

The grain transfer protocol presents a step-by-step guide on how to successfully transfer positioned grains from a single-grain luminescence disc to a scanning electron microscope (SEM) specimen stub and how to transport them between laboratories. Single-grain luminescence analysis allows the determination of luminescence characteristics for individual sand-sized grains. By combining such luminescence data with other grain properties such as geochemical composition, shape, or structure also at single-grain level, it is possible to investigate factors controlling luminescence signals or study other material properties. The non-luminescence properties are typically measured in another instrument; thus, grains need to be transferred between machines and sample holders, and sometimes also between laboratories. It is then important that the position of each grain is known and stable so that the properties from the same grain are compared. By providing an easily observable orientation marker on the specimen stub, the hundred numbered grains from the single-grain disc can be transferred and later identified when analyzed in the SEM.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ch. Mohana Rao ◽  
K. Mallikarjuna Rao

PurposeThe objective of the paper is to evaluate the fabrication process and to study the influence of process parameters of friction stir processing of 6061-TiB2-Al2O3 Aluminum alloy surface composite on microhardness tensile strength, and microstructure.Design/methodology/approachFriction stir processing method is used for attaining the desired mechanical properties, and selectively processed reinforcements to fabricate the samples. The Taguchi technique was used to optimize rotational speed, travel speed and volume percentage of reinforcement particles to enhance the mechanical properties of 6061-TiB2-Al2O3 Aluminum alloy composite.FindingsThe fabrication of surface composites through FSP allows new inventions in terms of material with enhanced surface layers without changing the base metal.Practical implicationsTo examine the behavior of the surface of the composites in the different zones, the practical implication consists of the use of different characterization techniques like optical microscopy and scanning microscopy for microstructural behavior and the measurement of hardness and tensile tests for mechanical behavior.Originality/valueThe research work consists of tool design and process parameters, which can affect the final product (microstructural changes), and the performance of the modified surface layer behavior was studied and presented.


2019 ◽  
Vol 50 (2) ◽  
pp. 133-148 ◽  
Author(s):  
Senthil Kumar ◽  
S Balachander

Process optimization is the key task of any engineering application to maximize the desirable output by optimizing the range of process parameters. In this research work, jute composites were fabricated by the hand lay-up method with the aim of optimizing the process parameter such as yarn linear density, fabric areal density and fabric laying angle on the mechanical properties of the textile composite structures using the Taguchi L9 orthogonal matrix. The plain-woven and twill-woven fabrics of Jute fabrics were produced through specialized handloom machine and used as preform for composite production. Epoxy resin was used as the matrix component. Signal-to-noise ratio ratio, analysis of variance and experimental verification of results were analysed. The results showed that fabric laying angle played major role to achieve high mechanical properties of composites and twill-woven structural reinforcement yields higher mechanical properties. Subsequent to this optimal process, parameters have been arrived for all the composites, and finally it was verified through the experimental results.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Deepak Doreswamy ◽  
Basavanna Shivamurthy ◽  
Devineni Anjaiah ◽  
N. Yagnesh Sharma

In the present research work, the effect of abrasive water jet (AWJ) machining parameters such as jet operating pressure, feed rate, standoff distance (SOD), and concentration of abrasive on kerf width produced on graphite filled glass fiber reinforced epoxy composite is investigated. Experiments were conducted based on Taguchi’s L27 orthogonal arrays and the process parameters were optimized to obtain small kerf. The main as well as interaction effects of the process parameters were analyzed using the analysis of variance (ANOVA) and regression models were developed to predict kerf width. The results show that the operating pressure, the SOD, and the feed rate are found to be significantly affecting the top kerf width and their contribution to kerf width is 24.72%, 12.38%, and 52.16%, respectively. Further, morphological study is made using scanning electron microscope (SEM) on the samples that were machined at optimized process parameters. It was observed that AWJ machined surfaces were free from delamination at optimized process parameters.


2016 ◽  
Vol 710 ◽  
pp. 155-159
Author(s):  
Mariem Zoghlami ◽  
Mohammad Jahazi ◽  
Victor Songmene

Since the invention of the friction stir welding, several studies have been conducted to understand the influence of process parameters on the microstructural, thermal and mechanical characteristics to improve the weld quality. Banded structures better known under the name of "onion rings" are one of phenomena that appear in the microstructure during this process. The welding parameters leading to their appearance as well as their effect on the quality of the joint are still subject to much research with different conclusions. In this context, the objective of this research work is to determine various characteristics of the ‘onion rings’ and correlate them to processing conditions.


Author(s):  
Shakeel Ahmed L. ◽  
Pradeep Kumar M.

Reaming is one of the finishing processes that have been widely applied in manufacturing industries. Reaming of Titanium Ti-6Al-4V alloy material is an important and current research topic on manufacturing processes. Optimal process parameter setting is an important element in the machinability study of Titanium Ti-6Al-4V alloy. Optimization has most significant importance, particularly for reaming operations. This research work focuses on the multi-response optimization of reaming process parameters using the Taguchi and Grey relational technique to obtain minimum cutting temperature (T), thrust force (Ft), torque (Mt), surface roughness (Ra) and hole quality. The experiments were performed on Titanium Ti-6Al-4V alloy using uncoated carbide straight shank reamer under wet and cryogenic LN2 conditions. Eighteen experimental runs (L18) based on the Taguchi method of orthogonal arrays were performed to determine the best factor level condition. The environment, cutting speed and feed rate were selected as control factors. Grey relational analysis was used to determine the most significant control factors affecting the output parameters. Grey relational grade obtained from the grey relational analysis was used to solve the reaming process with the optimal levels of the multiple performance characteristics responses were established. The optimum results indicate that the reaming results have been improved in wet coolant than the cryogenic LN2 condition.


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