Microwave cladding: A new approach in surface engineering

2014 ◽  
Vol 16 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Dheeraj Gupta ◽  
Apurbba Kumar Sharma
2009 ◽  
Vol 628-629 ◽  
pp. 447-452
Author(s):  
Peng Fei Lv ◽  
Ji Min Chen ◽  
F.R. Liu

Laser cladding has been developed as a useful technology to modify material surface in industry. In this paper a new approach of surface modification is introduced. Depositional Laser Cladding (DLC) was developed and the different mechanisms were investigated during the manufacture. Basing on particular analysis of defects in the experiment, the relation between the quality of cladding layer and laser energy density is manifested. Depositional effect and thermal effect play their roles in different place and the depositional effect provides thin layers with the thickness of near mean particle size. Appropriate parameters of laser energy can promote high quality, avoiding pores and stacks in agglomeration and ebullition. Controllable low thickness near mean particle size and sharp edge make it possible to be used on producing certain shape in the surface engineering field, such as restoring and gradient materials.


Author(s):  
K J Stout

This paper considers a new approach to controlling the finishing process of engineering surfaces to ensure that their final topography and surface mechanical properties make them suitable for the intended functional purpose. It is proposed that this ‘engineering’ of the final surface is achieved by controlling the final machining or surface working process to impart the required mechanical properties. It is shown in the paper that some surface engineering processes are already employed by industry but that many of these processes are implemented through an empirical understanding of them. The intention of the paper is to lay down a basis for a more rigorous approach to engineering surfaces for their final function.


2020 ◽  
Vol 404 ◽  
pp. 117-123
Author(s):  
Stephan Schirdewahn ◽  
Felix Spranger ◽  
Kai Hilgenberg ◽  
Marion Merklein

Within the scope of this work, a new approach named laser implantation process has been investigated, in order to improve the tribological performance of hot stamping tools. This surface engineering technology enables the generation of dome-shaped, elevated and highly wear resistant microfeatures on tool surfaces in consequence of a localized dispersing of hard ceramic particles via pulsed laser radiation. As a result, the topography and material properties of the tool and thus the tribological interactions at the blank-die interface are locally influenced. However, a suitable selection of hard ceramic particles is imperative for generating defect-free surface features with a high share of homogenously disturbed particles. For this purpose, different niobium (NbB2 and NbC) as well as titanium-based (TiB2 and TiC) materials were embedded on hot working tool specimens and subsequently analyzed with regard to their resulting shape and mechanical properties. Afterwards, modified pin-on-disk tests were carried out by using conventional and laser-implanted tool surfaces, in order to evaluate the wear and friction behavior of both tooling systems.


1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.


Author(s):  
V. Mizuhira ◽  
Y. Futaesaku

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.


Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
I.P. Shintaku ◽  
A.F. Sassoon

Immunoelectron microscopy of neoplastic lymphoma cells is valuable for precise localization of surface antigens and identification of cell types. We have developed a new approach in which the immunohistochemical staining can be evaluated prior to embedding for EM and desired area subsequently selected for ultrathin sectioning.A freshly prepared lymphoma cell suspension is spun onto polylysine hydrobromide- coated glass slides by cytocentrifugation and immediately fixed without air drying in polylysine paraformaldehyde (PLP) fixative. After rinsing in PBS, slides are stained by a 3-step immunoperoxidase method. Cell monolayer is then fixed in buffered 3% glutaraldehyde prior to DAB reaction. After the DAB reaction step, wet monolayers can be examined under LM for presence of brown reaction product and selected monolayers then processed by routine methods for EM and embedded with the Chien Re-embedding Mold. After the polymerization, the epoxy blocks are easily separated from the glass slides by heatingon a 100°C hot plate for 20 seconds.


Author(s):  
W. A. Chiou ◽  
N. Kohyama ◽  
B. Little ◽  
P. Wagner ◽  
M. Meshii

The corrosion of copper and copper alloys in a marine environment is of great concern because of their widespread use in heat exchangers and steam condensers in which natural seawater is the coolant. It has become increasingly evident that microorganisms play an important role in the corrosion of a number of metals and alloys under a variety of environments. For the past 15 years the use of SEM has proven to be useful in studying biofilms and spatial relationships between bacteria and localized corrosion of metals. Little information, however, has been obtained using TEM capitalizing on its higher spacial resolution and the transmission observation of interfaces. The research presented herein is the first step of this new approach in studying the corrosion with biological influence in pure copper.Commercially produced copper (Cu, 99%) foils of approximately 120 μm thick exposed to a copper-tolerant marine bacterium, Oceanospirillum, and an abiotic culture medium were subsampled (1 cm × 1 cm) for this study along with unexposed control samples.


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