Surface Roughness

It is the objective of this article to investigate the influence of surface preparation on the cold roll bonding (CRB) process. In this context, the effects of surface preparation parameters consisting of surface preparation method, surface roughness, scratch-brushing parameters, and the delay time between surface preparation and rolling are investigated on the bond strength of aluminum strips. The bond strength of two adjacent aluminum strips produced by the CRB process is evaluated by the peeling test. Furthermore, the interface region is investigated by metallographic observations. Our findings indicate that higher surface roughness values and shorter delay times improve the bond strength. It is also found that degreasing followed by scratch-brushing yield the best bonding properties.

Dry machining is a machining process with out coolant, and it has become more popular as a finishing process. Thus, it is especially crucial to select the machining parameters to obtain the desired surface finish of machined component. In the present investigation, the influence of process parameters like speed, feed and depth of cut in dry-machining, are studied as surface roughness as the output response variable. The concept of Design of Experiments (DOE) was used for necessary experimentation. En31 bearing steel material was considered in the present study. The experimental results were analyzed statistically to study the influence of process parameters on surface roughness.

Ductile iron can acquire enhanced thermal and mechanical properties from austempering heat treatment. The present study aims to identify the function of different cutting parameters affecting machinability and to quantify its effects. Turning was performed to test machinability according to the ISO3685-1993 (E) standard. After austenitizing at 900 °C for 90 min, austempered ductile iron (ADI) specimens were quenched in a salt bath at 380 °C for 90 min. The cutting force signals along three directions were measured in real time, whereas flank wear and surface roughness were measured offline. For the cutting parameters, the cutting speed and depth of cut were varied, but the feed rate was kept constant. In the flank wear tests, machining length was corresponded to tool life. In addition, in order to find out the effect of cutting parameters on surface roughness (Ra), tangential force (Ft), and flank wear (VB) during turning, response surface methodology (RSM) was utilized by using exp...

A model to study the effect of the roughness at the poly-Si/SiO/sub 2/ interface in silicon inversion layers on the electron mobility is obtained. Screening of the resulting perturbation potential by the channel carriers is taken into account, considering Green's functions for metal-oxide-semiconductor (MOS) geometry, i.e. taking into account the finite thickness of the gate oxide. Mobility of electrons is evaluated at room temperature by the Monte Carlo method, taking into account the simultaneous contribution of phonon scattering, SiO/sub 2//Si interface roughness scattering, Coulomb scattering and remote surface roughness scattering. The contribution of excited subbands is considered. The resulting remote surface roughness scattering is shown to be strongly dependent on the oxide thickness, and degrades mobility curves at low inversion charge concentrations. The results obtained show that the effect of this scattering mechanism cannot be ignored when the oxide thickness is below 5 nm, (as in actual devices), even when (as is usual) very high doping concentrations are used.

The possibility of developing a photochemical setup on the basis of an optically pumped ammonia laser with an intracavity photoreactor is proved. The obtained values of the cavity 'implication' factor γ are comparable with those of intracavity systems based on a CO2 laser. The conditions for achieving the maximum energy in the focusing cavity are determined and the ways to control the shape of its caustic are indicated.

The electron and hole mobility of Si complementary metal on oxide field effect transistors (CMOS) can be enhanced by introducing a biaxial tensile stress in the Si channel. This paper outlines several key analytical techniques needed to investigate such layers. Raman scattering is used to measure the strain in the Si channel as well as to map the spatial distribution of strain in Si at a lateral resolution better than 0.5 μm. Atomic force microscopy (AFM) is used to measure the surface roughness. Transmission electron microscopy (TEM) is used to reveal dislocations in the structure, the nature of the dislocations and the propagation of the dislocations. Secondary ion mass spectrometry (SIMS) is used to monitor the Ge content profile in the structure and the thickness of each layer. In the long term, inline nondestructive techniques are desired for epi-monitoring in manufacturing. Two techniques, spectroscopic ellipsometry (SE) and x-ray reflectivity (XRR), have shown promise at this stage.

Aim: This study aim to investigate the effect of a denture cleanser on hardness, roughness and tensile bond strength of a rigid (Kooliner) and a soft denture liner (Elite Soft) after 7, 60 and 120 days of immersion. Methods: Thirty circular and twenty rectangular specimens of each material were randomly distributed in two groups: control-immersion in artificial saliva at 37 C; and experimental-immersion in artificial saliva at 37ºC combined with immersion in the cleanser for 5 min. Hardness was measured using either a Vickers or Shore A ...

Abrasive flow finishing (AFF) is one of the widely used advanced finishing processes in which a small quantity of work material is removed by flowing semisolid abrasive-laden putty over the workpiece surface to be finished. AFF is popular for finishing ...

In this present work, an experimental investigation through mathematical modelling was carried out to study the effects of different cooling mediums and cutting parameters on surface roughness and cutting forces, during the hardturning of hardened AISI 52100 steel ( 60±2) HRC. Experiments were performed using PCBN insert under dry and compressed air cooling medium. Experimental observations indicates that hard turning under compressed air cooled condition produced lower values of surface roughness and cutting forces. However, there is no significant effect of cutting speed on the surface roughness. Compressed air lubrication have proved to be more productive with better surface finish and reduced cutting forces. It has been observed that surface roughness gets affected mostly by feed and not by depth of cut. Cutting forces changing randomly as per change in cutting speed.

Original scientific paper In the paper there is described the AISI 316L stainless steel surface obtained after electrochemical treatment in concentrated HNO3. It was characterized by roughness parameters, corrosion protection behaviour and chemical composition of the surface layer. Generally used 2D and 3D roughness parameters describing the surface after the electrochemical treatment are the following: Ra = 0.737 µm and Sa = 1,13 µm as well as Rq = 0,895 µm and Sq = 1,37 µm. In case of corrosion studies the passive current density was equal to 2,3×10 ̶ 2 µA/cm2, pitting potential was equal to Epit = 1140 mV vs. SCE and re-passivation potential was 79 mV vs. SCE. In the surface layer there were detected compounds of iron, chromium, molybdenum, cobalt, manganese, as well as calcium (contamination). The high resolution XPS spectra/results data have shown that most of detected iron compounds can be described as Fe2O3/FeOOH and chromium compounds as Cr2O3/CrOOH. The molybdenum detected ...

The surface geometry of the material is complicated to be determined. Numerical contact simulations of surface roughness are commonly performed by a simple model of asperities, however, most models use broad assumptions to determine the shape and size of asperity. This study presents a method for producing deterministic rough surfaces in ABAQUS by pre-processing on SOLIDWORKS using the curved wizard method. Random geometry of real surface roughness and rigid smooth balls was contacted in the simulation using finite element analysis. The outcomes were presented in the contact areas and surface topographic plots. Afterwards, the experimental results were compared to form the surface roughness of the finite element. The simulation results using the curved wizard method showed that the contact area and surface topography were identical to the experimental results on the y-axis at x = 288 m. This technique was combined with the model of real surfaces in ABAQUS, provided the surface roughness that is identical to the real surfaces. The deformed and undeformed topographic results were also identical to the actual experimental results with an error of 4.3%. The contact area that occurs is also the same as the experimental results.

Recently all environmental worries are calling for reducing the usage of fluids in machining operations. One of the promising solutions that appeared lately is minimum quantity lubrication (MQL). This research aimed to develop an eco-friendly cooling system for a lathe machine and assess its performance. After considering the customer needs, the needs were translated into engineering specifications in the conceptual design phase, and then the quality function deployment was developed. Three concepts were generated and evaluated considering the selection criteria, and a final concept was selected using the decision matrix method. Following this, a detailed design and fabrication of the subsystems such as the oil tank and a structure accommodate all the components. The developed system was tested on six different workpiece samples to compare the MQL system with the conventional one. In general, the MQL system resulted in lower surface roughness values as well as lower tool wear.