Klasifikacija tehničkih materijala prema klasama obradivosti kod hidroabrazivnog rezanja

This paper presents the major cutting knowledge, the opinion data and the results of actual theoretic parameters solutions and the current results, estimated by contemporary needs of hydro abrasive cutting technology. Here is a newly opened and discussed question of current data terminology disunity in the area of metrology topography surfaces of cutting walls created by abrasive waterjet.U radu su prezentirana temeljna znanja, razmišljanja i rezultati teorijskih rješenja vezano uz trenutne procijenjene suvremene potrebe za hidroabrazivnom tehnologijom rezanja. Ovdje je i ponovo otvoreno pitanje trenutne terminologije u području mjeriteljstva topografi je površina dobivenih rezanjem abrazivnim vodenim mlazom

Utjecaj poprečne brzine na nepravilnosti površine dobivene abrazivnim rezanjem vodenim mlazom

The paper deals with the calculation of the optimal traverse speed for diff erent types of materials, which is very important for predication, imaginings and dimensioning of technological factors and selection of the materials with the aim to increase of surface quality at abrasive waterjet cutting (AWJ) technology. The surface irregularities of the experimental used materials AISI 304, AISI 309 have been measured by non-contact shadow method. New empirically compiled equations of the infl uence of the traverse speed on tensometrical state of cut, deformation resistance of material and surface roughness Ra are at AWJ cutting available.Rad se bavi proračunom optimalne brzine rezanja za različite vrste materijala, što je vrlo važno za predikaciju, osmišljanje i dimenzioniranje tehnoloških čimbenika i izbor materijala s ciljem da se poveća kvaliteta površine reza tehnologijom abrazivnim vodenim mlazom (AWJ). Površinske nepravilnosti eksperimentalno korištenih materijala AISI 304, AISI 309 su mjerene bezkontaktnom metodom sjene. Dobivena je nova empirijska jednadžbe utjecaja brzine na tenzometrijsko stanje rezne površine, deformacijsku otpornost materijala i površinsku hrapavost Ra kod AWJ rezanja

Analiza topografije površina titanove legure nakon rezanja vodenim mlazom pomoću spektralne analize

Experimental study of a titan grade 2 surface topography prepared by abrasive waterjet cutting is performed using methods of the spectral analysis. Topographic data are acquired by means of the optical profilometr MicroProf®FRT. Estimation of the areal power spectral density of the studied surface is carried out using the periodogram method combined with the Welch´s method. Attention is paid to a structure of the areal power spectral density, which is characterized by means of the angular power spectral density. This structure of the areal spectral density is linked to the fi ne texture of the surface studied.Eksperimentalna studija površine titana klase 2 dobivene abrazivnim rezanjem vodenim mlazom je provedena korištenjem metode spektralne analize. Topografski su podaci prikupljeni pomoću optičkog profi lometra MicroProf®FRT. Procjena površinske snage spektralne gustoće je provedena periodogram metodom u kombinaciji sa Welch metodom. Pozornost je posvećena površinskoj snazi spektralne gustoće koja je karakterizirana pomoću kutnih spektara gustoće snage. Struktura površinskog spektra gustoće je povezana sa istraživanom fi nom teksturom površine

Investigation of selected surface integrity features of duplex stainless steel (DSS) after turning

The article presents surface roughness profiles and Abbott - Firestone curves with vertical and amplitude parameters of surface roughness after turning by means of a coated sintered carbide wedge with a coating with ceramic intermediate layer. The investigation comprised the influence of cutting speed on the selected features of surface integrity in dry machining. The material under investigation was duplex stainless steel with two-phase ferritic-austenitic structure. The tests have been performed under production conditions during machining of parts for electric motors and deep-well pumps. The obtained results allow to draw conclusions about the characteristics of surface properties of the machined parts

Investigation of sandwich material surface created by abrasive water jet (AWJ) via vibration emission

The paper presents research a of abrasive waterjet cutting of heterogeneous “sandwich“ material with different Young modulus of elasticity of the cutted surface geometry by means of vibration emission. In order to confirm hypothetical assumptions about direct relation between vibration emission and surface quality an experiment in heterogeneous material consisting of stainless steel (DIN 1.4006 / AISI 410) and alloy AlCuMg2 has been provided

Influence of argon pollution on the weld surface morphology

In this paper the surfaces of butt welded joints in steel tubes were analyzed using an optical 3D measurement system to determine the morphology and topographic parameters. It was established that pollution of the argon shield gas with oxygen did not influence the width of the heat-affected zone. However, the composition of the shield gas significantly influenced the surface asymmetry, Ssk, and its inclination Sku. The measurement of these parameters enabled the selection of a higher quality surface, which was visually proven by the reduction in discoloration of the surface of the weld joint. High quality surfaces eliminate a potential habitat for bacteria and a future source of corrosion as well as providing less resistance to fluid flow

Investigation of sandwich material surface created by abrasive water jet (AWJ) via vibration emission

The paper presents research a of abrasive waterjet cutting of heterogeneous “sandwich“ material with different Young modulus of elasticity of the cutted surface geometry by means of vibration emission. In order to confirm hypothetical assumptions about direct relation between vibration emission and surface quality an experiment in heterogeneous material consisting of stainless steel (DIN 1.4006 / AISI 410) and alloy AlCuMg2 has been provided

Monitoring of focusing tube wear during abrasive waterjet (AWJ) cutting of AISI 309

The paper deals with the investigating the possibility of using vibrations as a potential source of information for the detection of the malfunctions during the abrasive supplying and focusing tube wear in the process of AWJ. The tested material was the stainless steel AISI 309. Variable factors in the experiment were the abrasive mass flow ma and the focusing tube diameter df. The scanned vibration signal of the material was subjected to frequency analysis. With the increase of the abrasive mass flow, the shift of the amplitudes will follow the opposite direction and decrease. Frequency spectra of all assessed signals are similar by shape in the high-frequency area

Performance Analysis of Pulsating Water Jet Machining During Disintegration of Rocks by Means of Acoustic Emission

Over the decades, water jet cutting has been widely used for rock disintegration in mining operations and quarrying purposes. The impact of high-pressure water jet on hard material like rock, coal ruins the original structure of the material; therefore, low-pressure water jet comes into the existence. In recent year, pulsating water jet has been applied in numerous ways such as surface cleaning, exclusion of damaged material layers, preparation of surfaces, and disintegration of mate rials. It has also a great potential for application in hard rock breakage as conventional methods are cumbersome, not readily accessible and have economical limitations. The performance of the jet increases significantly by the generation of pulses causing disintegration of material at a relatively lower energy and costs. This paper focuses on the study of the disintegration processes of marble and granite by pulsating water jet subjected to erosion via acoustic emission. The experiments are performed by using pulsating water jet with modulation frequency of 20.20, kHz. The MVT circular nozzle with an orifice diameter of 0.9, mm, standoff distance from the target material 6, mm, traverse speed varied from 2 to 16, mm/s, and pump pressure 60, MPa was used for water jetting. The topography of granites and marble on the cut depth and surface quality were investigated by the optical profile meter. Moreover, dependable relations between some physical and mechanical properties of the rocks and the depth of cut were observed. The online monitoring of acoustic emission shows the change in response to the pulse frequency at different time intervals

The use of opto-digital microscope for analysis Of the PFA-based abrasive tools with surface micro-discontinuities

This paper presents the results of study using a modern opto-digital microscopis technique to observe, measure and analyses the active surface of ceramic grinding wheels made from pink fused alumina grains with a technical designation 1-35×20×10-CrA/F80J7V. The grinding wheels used in the experiments had special active surface micro-discontinuities in a form of grooves from 0.5 to 1.5 mm deep, shaped deliberately using abrasive water-jet technology. The measurements of these characteristic elements were made using an advanced opto-digital microscope DSX500 by Olympus, equipped with the dedicated software STREAM Motion Desktop 1.8. This equipment made it possible to perform basic geometric analyses of the acquired grinding wheel surface images. They were carried out particularly in relation to some of the characteristic elements of structure of the grinding wheel such as micro-discontinuities, PFA abrasive grains, free intergranular spaces. Positive results from these tests confirmed the possible application of this microscopic technique within broadly defined diagnostics of abrasive tools.Keywords: Opto-digital microscopy, Pink Infused Alumina, Grinding wheel, Surface micro-discontiniuitie