scholarly journals Problems of blackening of steel parts in technical practice

2018 ◽  
Vol 244 ◽  
pp. 01012 ◽  
Author(s):  
Sylvia Kuśmierczak ◽  
Martin Makovský
Keyword(s):  
Electron Microscopy ◽  
Surface Quality ◽  
Complex Analysis ◽  
Light And Electron Microscopy ◽  
Great Influence ◽  
Production Flow ◽  
Degradation Processes ◽  
Technical Practice ◽  
Surface Oxides

Problems of degradation are mainly solved in finished products, in a number of cases it is manifested during production. A great influence on the degradation processes of the products has the surface quality and surface finish. The article deals with the problem of blackening of steel, which has been treated with alkaline blackening. The throttle shaft made of automatic steel will be analyzed. Degradation was manifested by a change in surface quality after alkaline blackening. The methods of light and electron microscopy in combination with complex analysis of production flow and technology conditions were used for analysis. Based on the results of analyzes it was found that the degradation processes are closely related to the quality of preparation of the surface. Owing to the incorrect pretreatment of the surface, oxides occurred locally. At the sites of oxides, after alkaline blackening, the surface layer was peeled off, resulting in deterioration in the quality of the product.

scholarly journals Experimental Research into Technology of Abrasive Flow Machining Nonlinear Tube Runner

2014 ◽  
Vol 6 ◽  
pp. 752353 ◽  
Author(s):  
Junye Li ◽  
Lifeng Yang ◽  
Weina Liu ◽  
Xuechen Zhang ◽  
Fengyu Sun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Quality ◽  
Experimental Research ◽  
The Self ◽  
Technological Parameters ◽  
Abrasive Flow Machining ◽  
Overall Performance ◽  
Scanning Electron

In the fields of military and civil uses, some special passages exist in many major parts, such as non-linear tubes. The overall performance is usually decided by the surface quality. Abrasive flow machining (AFM) technology can effectively improve the surface quality of the parts. In order to discuss the mechanism and technology of abrasive flow machining nonlinear tube, the nozzle is picked up as the researching object, and the self-designed polishing liquid is employed to make research on the key technological parameters of abrasive flow machining linear tube. Technological parameters’ impact on surface quality of the parts through the nozzle surface topography and scanning electron microscopy (SEM) map is explored. It is experimentally confirmed that abrasive flow machining can significantly improve surface quality of nonlinear runner, and experimental results can provide technical reference to optimizing study of abrasive flow machining theory.

scholarly journals Investigation of Surface Quality in Cost of Goods Manufactured (COGM) method of µ-Al2O3 Powder-Mixed-EDM Process on Machining of Ti-6Al-4V

2021 ◽  
Author(s):  
Aboulfazl Taherkhania ◽  
Mohsen Asghari Ilani ◽  
Faramarz Ebrahimi ◽  
Phan Huu Nguyen ◽  
Long Banh Tien ◽  
...  
Keyword(s):  
Surface Quality ◽  
Lower Surface ◽  
Dielectric Medium ◽  
Dielectric Fluid ◽  
Powder Concentration ◽  
Surface Oxides ◽  
Micron Size ◽  
Deep Cavities ◽  
Edm Process

Abstract It is very essential to form such high stregth and hard-to-cut materials by using modern machining methods. It is important to introduce the efforts on modification of the process for improving the machining quality. In the present investigation, an effort was made to analyze the effects of micro size aluminium particles mixed dielectric medium under different powder concentration on machining titanium alloy in electro erosion process. The response-surface-methodology(RSM) based algorithm was utilized to analyze the performance measures by considering machinning time with Cost of Goods Manufactured (COGM) method in PMEDM process. It was found that the micron size powders can significantly help to enhance the surface quality of the Ti-6Al-4V surface during machining in EDM process. The presence of carbon, oxygen elements and the formation of surface oxides and carbides has been found due to the decomposition of dielectric fluid in PMEDM process. The lower deep cavities and uniform machining surface have been produced with the aluminum oxide powder EDM process owing to lower surface cracks density, conductivity. To sum up, investigation and comparison of surface scanning showed that this setting has been implied could be considered by the industries needs more precision.

Analysis of Causes of Defects Appearance in Wire Drawing

2020 ◽  
Vol 405 ◽  
pp. 217-222
Author(s):  
Jiří Švejcar ◽  
Martin Juliš ◽  
Lenka Klakurková ◽  
Pavel Gejdoš ◽  
Tomáš Zikmund
Keyword(s):  
Electron Microscopy ◽  
Computerized Tomography ◽  
Intermediate Product ◽  
Complex Analysis ◽  
Light And Electron Microscopy ◽  
Hardness Measurement ◽  
Wire Drawing ◽  
Forming Process ◽  
Fine Grain

In the manufacture of wires designed for the welding of low-alloy fine-grain steels, multiple internal discontinuities appear during some periods that are the cause of major failures (cracking) of the wires. To establish the causes of this phenomenon, a complex analysis was performed making use of light and electron microscopy, metallography, microfractography, computerized tomography and hardness measurement. The analysis revealed that wire cracking in course of wire drawing was due to the superposition of the effects of an inappropriate structure of the initial intermediate product (the presence of polyhedral grains of hard bainitic phase) and unsuitable conditions of the forming process.

Experimental Study on Csf/AZ91D Composite Using Extrusion Following Vacuum Infiltration Method

2010 ◽  
Vol 97-101 ◽  
pp. 382-385 ◽  
Author(s):  
Jun Tao Guan ◽  
Le Hua Qi ◽  
Li Zheng Su ◽  
Jian Liu
Keyword(s):  
Surface Quality ◽  
Great Influence ◽  
Extrusion Process ◽  
Vacuum Infiltration ◽  
Extrusion Temperature ◽  
Measuring System ◽  
Infiltration Process ◽  
Good Surface ◽  
Deformation Stages

10vol. % Csf/AZ91D composites were fabricated by extrusion following vacuum infiltration process with self-developed experimental device and measuring system. The relationships of load vs displacement during process and surface quality of composites at various extrusion temperatures were investigated. SEM microscope was used to observe the microstructure of fabricated composites. The experimental results showed that the extrusion process can be divided into three deformation stages. The extrusion temperature had a great influence on the maximum extrusion load. Based on proper infiltration parameters, a extruded bar with good surface quality was obtained at extrusion temperature of 420°C.

Monitoring the surface quality of silver plasmon waveguides with nonlinear photoemission electron microscopy and in-situ ion sputtering

2017 ◽  
Vol 183 ◽  
pp. 55-60
Author(s):  
Kellie Pearce ◽  
Francis Schuknecht ◽  
Christian Späth ◽  
Benjamin Duschner ◽  
Florian Richter ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Quality ◽  
Ion Sputtering ◽  
Photoemission Electron Microscopy ◽  
Photoemission Electron

scholarly journals Investigation of the Effect of Vibration Characteristics on the Grinding Performance of Aero-Engine Blade Tip

2021 ◽  
Author(s):  
Wei Li ◽  
Qidi Chen ◽  
Jian Wu ◽  
Mingjia Liu ◽  
Yinghui Ren ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Great Influence ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Aero Engine ◽  
Engine Blade ◽  
Blade Tip ◽  
The Difference

Abstract The machining quality of the blade tip has a great influence on the service performance and life of the aero-engine blade. The recent paper investigates the effect of vibration during the grinding process of the GH4169 nickel-based superalloy blade tip. Moreover, this paper proposes a theoretical model to link the unbalance of the grinding wheel, the vibration, and the surface topography characteristics of the blade. The results show that the blade vibration during grinding and the resulting non-linear change of the grinding depth could reduce the surface quality of the blade tip, and lead to differences in the surface quality of the blade tip in different areas, where the surface roughness in the entry area zone I is the largest, in the exit area zone III is the second largest, and the intermediate area zone III is the smallest. Grinding depth has a greater impact on the difference of the surface quality in the blade tip grinding process, especially when the grinding depth is greater than 4 μm, the difference of surface roughness increases significantly. On the other hand, the feed rate has little effect on the difference in surface quality. Adding damping block can reduce the surface roughness of the blade tip, however, it does not reduce the difference in surface quality.

The Polishing Process of Cylindrical Rollers by Using a Double-Side Lapping Machine

2013 ◽  
Vol 589-590 ◽  
pp. 447-450 ◽  
Author(s):  
Wen Hua Zhou ◽  
Wei Feng Yao ◽  
Ming Feng ◽  
Bing Hai Lv ◽  
Qian Fa Deng
Keyword(s):  
Surface Quality ◽  
Cylindrical Surface ◽  
Smooth Surface ◽  
Great Influence ◽  
Working Life ◽  
Geometric Accuracy ◽  
Polishing Process ◽  
Rolling Bearings ◽  
Lapping Machine

The surface quality of cylindrical rollers has a great influence on the working life of rolling bearings. In the paper, double-side lapping machine and flannelette pads are applied to polish the cylindrical surface of rollers. After 20 min polishing, rollers with smooth surface are obtained and the roundness of the rollers have a improvement of about 0.3 μm, which means that the polishing process based on double-side lapping method can effectively improve the surface quality and geometric accuracy of cylindrical rollers.

Effect of Pattern-Less Forming Process on Quality of Sand Mold Surface

2020 ◽  
Vol 1001 ◽  
pp. 115-120
Author(s):  
Li Jun Guo ◽  
Zhong De Shan ◽  
Er Biao Jiang
Keyword(s):  
Surface Quality ◽  
Great Influence ◽  
Sand Mold ◽  
Extrusion Force ◽  
Mold Surface ◽  
Object Surface ◽  
Forming Process ◽  
Abrasive Resistance ◽  
Sand Material

The pattern-less sand mold was used as the research object, surface quality of sand mold was carried out by using surface abrasion tester. In this paper, the influence of sand material such as the types of sand, resin contents and extrusion pressure on the surface quality was studied through the single-factor test. The results showed that: different sand mold had different surface abrasive resistance. The angle coefficient of sand has a great influence on the surface abrasive resistance of the sand mold. With the increase of extrusion force, the surface abrasive resistance of sand mold increased. And as the resin content increased, the surface abrasive resistance of sand mold continued to increase.

scholarly journals Solving the Issue of Discriminant Roughness of Heterogeneous Surfaces Using Elements of Artificial Intelligence

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2620
Author(s):  
Milena Kubišová ◽  
Vladimír Pata ◽  
Dagmar Měřínská ◽  
Adam Škrobák ◽  
Miroslav Marcaník
Keyword(s):  
Neural Networks ◽  
Surface Quality ◽  
Statistical Parameter ◽  
Measured Data ◽  
Metallic Materials ◽  
Heterogeneous Surfaces ◽  
Roughness Parameters ◽  
Technical Practice ◽  
Hidden Layer

This work deals with investigative methods used for evaluation of the surface quality of selected metallic materials’ cutting plane that was created by CO2 and fiber laser machining. The surface quality expressed by Rz and Ra roughness parameters is examined depending on the sample material and the machining technology. The next part deals with the use of neural networks in the evaluation of measured data. In the last part, the measured data were statistically evaluated. Based on the conclusions of this analysis, the possibilities of using neural networks to determine the material of a given sample while knowing the roughness parameters were evaluated. The main goal of the presented paper is to demonstrate a solution capable of finding characteristic roughness values for heterogeneous surfaces. These surfaces are common in scientific as well as technical practice, and measuring their quality is challenging. This difficulty lies mainly in the fact that it is not possible to express their quality by a single statistical parameter. Thus, this paper's main aim is to demonstrate solutions using the cluster analysis methods and the hidden layer, solving the problem of discriminant and dividing the heterogeneous surface into individual zones that have characteristic parameters.

scholarly journals Microwave Protocols for Plant and Animal Paraffin Microtechnique

2005 ◽  
Vol 13 (3) ◽  
pp. 50-53 ◽  
Author(s):  
Denise Schichnes ◽  
Jeffrey A. Nemson ◽  
Steven E. Ruzin
Keyword(s):  
Electron Microscopy ◽  
Microwave Field ◽  
Light And Electron Microscopy ◽  
Microwave Oven ◽  
Power Supplies ◽  
Microwave Technology ◽  
Processing Times ◽  
Field Uniformity ◽  
Variable Power

The microwave oven is a valuable tool for light and electron microscopy microtechnique labs. Tissue processing times, traditionally taking up to two weeks, have been reduced to a few hours as a result of the implementation of microwave technology (Kok et al., 1988, Gibberson and Demaree, 2001). In addition, the quality of the tissue preparations has improved dramatically. Microwave ovens have also evolved since their first use in the laboratory. Early experiments were conducted using relatively crude commercial microwave ovens. Now, labs use microwave ovens with temperature probes, strict control over the magnetron (which generates the microwaves), variable power supplies, chamber cooling, and high microwave field uniformity.

Sign in / Sign up

Export Citation Format

Share Document