INVESTIGATION ON HIGH-TEMPERATURE OXIDIZATION OF MIRROR-QUALITY GROUND STAINLESS STEEL

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3005-3010 ◽  
Author(s):  
KAZUTOSHI KATAHIRA ◽  
HITOSHI OHMORI ◽  
MASAYOSHI MIZUTANI ◽  
JUN KOMOTORI
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
High Temperature ◽  
High Quality ◽  
Spinel Type ◽  
Combined Process ◽  
Elid Grinding ◽  
Modification Method ◽  
Quality Surface ◽  
High Quality Surface

To investigate the possibility of developing a new surface modification method by the combined process of ELID grinding and high-temperature oxidization, we treated ELID finished specimens and polished specimens by high-temperature oxidization in the atmosphere and performed detailed analysis to determine how the treatment would change the specimen surfaces. The ELID-series showed high quality surface roughness and excellent tribological characteristics as compared with the polished-series. The improved surface properties of the ELID-series seem to result from formation of fine, uniform structures of spinel-type multiple oxides FeCr 2 O 4 and Cr 2 O 3 on the surface by high-temperature oxidization.

Chemical Mechanical Polishing of Transparent Nd:YAG Ceramics

2008 ◽  
Vol 375-376 ◽  
pp. 278-282 ◽  
Author(s):  
Jun Li ◽  
Yong Zhu ◽  
Chuang Tian Chen
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscope ◽  
Chemical Mechanical Polishing ◽  
Brittle Materials ◽  
Mechanical Polishing ◽  
High Quality ◽  
Atomic Force ◽  
Hard And Brittle Materials ◽  
Quality Surface ◽  
High Quality Surface

Transparent Nd:YAG ceramics which are very hard and brittle materials, are very difficult to be polished. There are many micro scratches or damages on the surface after mechanical polishing with Al2O3. In order to remove micro scratches or damages, chemical mechanical polishing (CMP) was adopted to manufacture Nd:YAG ceramics. In the polishing experiment, Pellon and Chemcloth pads were utilized for chemical mechanical polishing of Nd:YAG ceramics. Colloidal SiO2 was selected as the polishing slurry in two different polishing environments, acidity and alkalinity. The surface roughness was determined by using atomic force microscope. In this study, four polishing experimental combinations that each combination contains one of the two pads and one of the two polishing environments were carried out in the optimum polishing condition. Then the high quality surface of transparent Nd:YAG ceramics with the best surface roughness of < 0.2 nm RMS and few micro scratches or damages is obtained by adopting CMP process with Chemcloth pad and colloidal SiO2 in acidic condition.

scholarly journals Ultra-Precision Machining of Tungsten-Based Alloys by Cutting and Burnishing

2011 ◽  
Vol 5 (3) ◽  
pp. 320-325 ◽  
Author(s):  
Naohiko Sugita ◽  
◽  
Kazuhiko Nishioka ◽  
Mamoru Mitsuishi
Keyword(s):  
Surface Roughness ◽  
Cutting Tool ◽  
Tungsten Alloy ◽  
Precision Machining ◽  
Binder Phase ◽  
High Quality ◽  
Cnc Lathe ◽  
Ultra Precision ◽  
Quality Surface ◽  
High Quality Surface

This paper proposes ultra-precision machining of tungsten alloy maximizing burnishing between the cutting tool and workpiece during cutting by combining strengths of the crystal grain and binder phase. Turning experiments conducted using workpieces of tungsten-based alloys 50 mm in diameter and 10 mm thick produced high-quality surface roughnessRzof 0.13 µm, achieved on a CNC lathe.

scholarly journals Laser Cutting of Austenitic Corrosion-Resisting Steels

2019 ◽  
Vol 2 (2) ◽  
pp. 93-98
Author(s):  
Gergely Halász ◽  
Enikő Réka Fábián ◽  
János Kuti
Keyword(s):  
Stainless Steel ◽  
Laser Beam ◽  
Laser Cutting ◽  
Optical Microscope ◽  
Solid State Laser ◽  
High Quality ◽  
Thick Plates ◽  
Steel Sheets ◽  
Quality Surface ◽  
High Quality Surface

Abstract Cutting of thick austenitic stainless steel sheets with a disc laser is not fully developed. In this research were investigated the surface of holes made on 3.25 mm thick stainless-steel cut with CO2 laser beam and disk laser beam. Using optical microscope and electron microscope to examine the cutting surfaces, were observed that the cutting with the CO2 laser result high quality surface (cutting 3,25 mm thick plates), but holes made with solid-state laser has microcracks on the inner side. These cracks are not acceptable to the customers.

scholarly journals Large-Scale and Deep-Seated Gravitational Slope Deformations on Mars: A Review

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 174
Author(s):  
Marco Emanuele Discenza ◽  
Carlo Esposito ◽  
Goro Komatsu ◽  
Enrico Miccadei
Keyword(s):  
Large Scale ◽  
High Quality ◽  
Surface Data ◽  
Geomorphological Processes ◽  
Gravitational Processes ◽  
Quality Surface ◽  
High Quality Surface ◽  
Mars Missions

The availability of high-quality surface data acquired by recent Mars missions and the development of increasingly accurate methods for analysis have made it possible to identify, describe, and analyze many geological and geomorphological processes previously unknown or unstudied on Mars. Among these, the slow and large-scale slope deformational phenomena, generally known as Deep-Seated Gravitational Slope Deformations (DSGSDs), are of particular interest. Since the early 2000s, several studies were conducted in order to identify and analyze Martian large-scale gravitational processes. Similar to what happens on Earth, these phenomena apparently occur in diverse morpho-structural conditions on Mars. Nevertheless, the difficulty of directly studying geological, structural, and geomorphological characteristics of the planet makes the analysis of these phenomena particularly complex, leaving numerous questions to be answered. This paper reports a synthesis of all the known studies conducted on large-scale deformational processes on Mars to date, in order to provide a complete and exhaustive picture of the phenomena. After the synthesis of the literature studies, the specific characteristics of the phenomena are analyzed, and the remaining main open issued are described.

scholarly journals Achieving high quality surface of laminated glass-reinforced plastics during milling

2018 ◽  
Vol 224 ◽  
pp. 01044 ◽  
Author(s):  
Daniel Rychkov ◽  
Dmitry Lobanov ◽  
Aleksey Kuznetsov
Keyword(s):  
Glass Fiber ◽  
Cutting Speed ◽  
Laminated Composite ◽  
High Strength ◽  
High Quality ◽  
Fiber Plastic ◽  
Flank Surface ◽  
Cutting Modes ◽  
Quality Surface ◽  
High Quality Surface

Milling is one of the most common ways of workpiece machining, but obtaining a high quality surface of laminated composite materials is difficult due to their layered structure, high strength characteristics and low heat conductivity. This poses a problem of creating a milling technology that provides a high quality surface. This research investigates STEF -1 glass-fiber plastic with fine grain structure processed on the equipment with high cutting speed. The object of the research is roughness Ra as a quality criterion. Our glass-fiber plastic milling experiments demonstrate that the surface quality depends to a large extent on the cutting modes and the wear level of the tool cutting edge which is determined by the size of the wear bevel on the flank surface. The blade of the cutting tool is established to wear unevenly during glass-fiber plastic processing as it interacts with two different materials. We recommend the wear bevel on the flank surface to be less than 0.35 mm to ensure the high quality of the laminated composite material surface. The cutting modes should be within the following range: feed per tooth is 0.15 ÷ 0.17 mm/tooth, cutting depth is 0.5 ÷ 0.9 mm, cutting speed is above 45 m/s, with the cutting part of the tool being made of high-strength instrumental materials.

Identification of the Initial Oxide Films on 18-8 Stainless Steel in High Temperature Water

CORROSION ◽  
1968 ◽  
Vol 24 (10) ◽  
pp. 336-337 ◽  
Author(s):  
T. NAKAYAMA ◽  
Y. OSHIDA
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Oxide Film ◽  
Oxide Films ◽  
Spinel Type ◽  
High Temperature Water ◽  
Temperature Water

Abstract Initial oxide film formed on 18–8 stainless steel in high temperature water at 300 C (572 F) for 1 hour was identical with corundum type crystals like (Cr, Fe)2O3 alone or its coexistence with α-Fe2O3. On the contrary, the oxide film produced by prolonged oxidation (24 hours) consisted mainly of the spinel type crystals containing nickel.

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