Applied Mechanics and Materials Vols. 110-116

Abstract: Ti film on AISI 201 was prepared by plasma. The film was characterized and analyzed by using a variety of analytical techniques, such as XRD, SEM and universal test machine. Ti films were deposited on AISI 201 stainless steel substrate, it was found that of Ti film has a different microstructure in various negative bias. And film density is connected with bias. When bias rose from the 15V to 100V, the film density increased from 3.82 g/cm³ to 4.28 g/cm³. After bias rose from the 100V to 180V, film density decreased from 4.28 g/cm³ to 4.13g/cm³. And also, due to the microstructural changes, the adhesiveness of Ti films at the AISI 201 increased from 1.16 MPa to maximum of 3.87 MPa, and then decreased. There is a similar maximum value of approximately 7.53 MPa at the AISI 304.

Abstract: In this study the effect of nanoclay (0, 3 and 5 wt %) and grafted anhydride maleic with polypropylene (MAPP, 3 and 5 wt%) on physical and mechanical properties of polypropylene/wood flour nanocomposite was investigated. For manufacturing of these composites after melt compounding of the material they were converted to wood plastic granules in extruder and placed in hot press. The results showed that with increase of nanoclay physical (thickness swilling and water absorption) properties increases significantly but mechanical (bending and module of elasticity) properties increase up to 3 percent but after that gradually decreases. Also with incorporation of MAPP physical and mechanical properties of this nanocomposites improved and this positive effect was stronger for 5 percent MAPP than 3 one.

Abstract: The tribological properties of Plasma Nitrided (PN) rings were examined in high vacuum environment (1.6 x 10^-4bar) at 25°C, 200°C and 400°C. The high vacuum based pin on disc tribometer was used for this investigation. The two different sliders namely austenitic stainless steel type AISI 316LN (316LN) pin and Nickel based alloy coated (Colmonoy) pin have been used. The tribological parameters such as friction coefficient, wear mechanism and wear rate have been evaluated. The PN 316LN rings exhibits excellent wear resistance against 316 LN pin and Colmonoy pin at all temperatures. However, the PN 316LN ring vs Colmonoy pin pair shows better wear resistance than PN 316LN ring vs 316 LN pin pair. Whereas the untreated 316 LN ring vs 316 LN pin pair exhibits the combination strong adhesion and plastic deformation wear mechanism.

Abstract: Friction stir processing (FSP) is an emerging surface modification technology for enhancing the sheet metal properties through microstructural refinement at a particular region which might undergo severe plastic deformation. The extruded AZ31B magnesium alloy used in this investigation exhibits very limited ductility accompanied by brittle like behavior at room temperature because of hexagonal packed structure and severe mechanical twinning. Hence, an attempt was made to study the effect of processing parameters such as tool rotational speed and tool traversing speed on tensile properties of friction stir processed AZ31B magnesium alloy. It is found that the friction stir processing of the Magnesium alloy improved the ductility of the material when compared to the base material and also produced an ultrafine equiaxed grain in the processed zone, an ideal condition for the material to exhibit superplasticity.

Abstract: Fabric compressibility is very important in all RTM processes, and affects both the material and processing properties of the part. As the fabric is compressed by fluid pressure or the mold surface the fibers get compacted and the fiber volume fraction increases. This decreases the thickness of the part, decreases the permeability, and decreases the porosity. Compressibility is possibly more important to understand in one sided molding processes than in closed-mold processes. In this study, changing in permeability for four types of fibers that have been under pressure is measured. Based on experimental data related to permeability changes, for each type of fibers, plotted corresponding curves using interpolation and for each sample, modeled its behavior. Finally, the model outputs for several samples compared with experimental data to evaluate precision of model. The results showed that this model with low error can predict the permeability changes of fibers.

Abstract: Manganese Phosphate is an Industrial coating used to reduce friction and improve lubrication in sliding components. In this study, the tribology behavior of uncoated, manganese phosphate coated, Manganese Phosphate with oil lubricant AISI D2 steels was investigated. The Surface morphology of manganese phosphate coatings was examined by scanning electron microscope (SEM) and Energy dispersive X-ray Spectroscopy (EDX) .The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The wear resistance of the coated steel were evaluated through pin on disc test using a sliding velocity of 0.35 m/s under normal load of 5 to35 N and controlled condition of temperature and humidity. The Coefficient of friction and wear loss were evaluated. Based on the results of the wear test, the manganese phosphate with lubricant exhibited the lowest average coefficient of friction 0.13 and the lowest wear loss 0.4 mm³ under 35 N load.

Abstract: Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its origin excellent corrosion resistance due to the nature of presence Cr as alloying element to form stable passive layer that protects the steel. Due to its inherent austenitic structure, this material has relatively low hardness as well as poor wear resistance which hinders a wider applicability of the material and may cause problems in existing applications. The gaseous thermochemical treatments to improve surface properties of material are typically carried out in carbon and/or nitrogen bearing gases and usually associated with temperature above 500 °C.

Abstract: In the present work, an attempt has been made to produce a wax blend which could offer a better surface finish. Experiments were conducted with different types of waxes namely paraffin wax, bees wax, montan wax, carnabua wax and ceresin wax by varying their proportions. In each case the surface roughness of wax pattern was determined. The experimental data obtained were used to optimize the quantity of the waxes to form a blend having minimum surface roughness. The effect of varying proportions of the aforesaid waxes on the surface roughness of the wax blends was investigated. Taguchi method was used to optimize the required composition of the waxes. Taguchi method has successfully suggested the required proportions of the aforesaid waxes for the blend which could offer the minimum surface roughness.

Abstract: Composite materials have a number of properties that make them attractive for use in aerospace applications. The impact behavior of fiber reinforced composite materials is much more complex than conventional metallic structures due to a number of different failure modes on the inter laminar and intra laminar level. The aim of this study is to investigate the effects of temperature and thermal residual stresses on the impact behavior and damage of glass/epoxy laminated composites. To this end, thermal stress analyses of the laminates with lay-ups [90/0/0/90] s, [90/0/45/45] s, [0/90/45/-45] s, [45/0/-45/90] s are carried out under different temperatures by using ANSYS software. Also, the impact analysis on the laminated composites was performed at the different range of impact energies under different temperatures. The specific energy values and impact parameters were obtained and compared for each type of specimens and temperatures.

Abstract: The paper presents the results of an investigation on aluminum-silicon (LM6) alloy using pressurized lost foam casting process. The study investigated the effect of pressure on casting integrity-geometry, eutectic silicon spacing, particle roundness and hardness. Following air pressures: 1bar, 2bar, 3bar and 4bar were applied on the solidifying alloy. The eutectic silicon spacing and particle roundness were measured using optical microscope which was equipped with image analyzer by averaging of at least ten results as well as Vickers hardness testing machine. For casting integrity-geometry all surfaces of solidified castings were captured by digital camera for better observation. The results show that applying pressure during solidification of the LM6 alloy has significant influence on casting integrity-geometry, eutectic silicon spacing, particle roundness and hardness of the alloy. By increasing the applied pressure, solidification time decline. Consequently, silicon spacing reduces as well as increasing of hardness. Besides, rising air pressure lead to fulfilling of molten which improves the casting integrity and particle roundness.