Formation of Globular Microstructure in A380 Aluminum Alloy by Cooling Slope Casting

International Conference on Advances in Materials and Processing Technologies (AMPT) -- OCT 26-29, 2009 -- Kuala Lumpur, MALAYSIAWOS: 000303492800046Thixoforming and related semi-solid processing (SSP) methods require thixotropic materials. One of the many SSP techniques is the cooling slope (CS) casting process, which is simple and has minimal equipment requirements, and which is able to produce feedstock materials for semisolid processing. When the feedstock is reheated to the semisolid temperature range, non-dendritic, spheroidal solid particles in a liquid matrix suitable for thixoforming are obtained. In this study, equipment for the CS technique was first established, and then the effects of the pouring temperature and inclined slope angle on the microstructures of A380 aluminum alloy (ISOAlSi8Cu3Fe) were studied. Optimum parameters for thixoforming experiments were selected, and it was found that the microstructure produced by the inclined plate depended on its angle and the pouring temperature

Experimental Investigation and Mathematical Modeling of Laser Deep Engraving Process for Microapplication

WOS: 000319075100023This paper investigates the effects of process parameters (laser power, scan speed, frequency and fill spacing) on the laser deep engraving of AISI 316 stainless steel. The optimum process conditions for minimization of the surface roughness and maximization of the engraving depth are also determined. An experimental investigation consisting of 108 different combinations is carried out to determine the process parameters which contribute engraved surface roughness and depth. The results indicate that both surface roughness and engraving depth significantly decrease with an increase in the scan speed and a decrease in the laser power. A second order regression model is also used to formulate the relationship between the parameters and process responses. The results of the regression analysis show that the calculated values from the regression model and measured values from the experiments are very similar. Moreover, the results suggest that the regression model might be used to predict the surface roughness and engraving depth.Ege UniversityEge University [35MUH08]We are grateful to Laser Mikron Ltd. Sti. company in Izmir-Turkey where laser tests performed. This work was supported by Ege University under project no. 35MUH08

SURFACE ROUGHNESS AND WEAR BEHAVIOR OF LASER MACHINED AISI H13 TOOL STEEL

International Conference on Advances in Materials and Processing Technologies (AMPT) -- OCT 26-29, 2009 -- Kuala Lumpur, MALAYSIAWOS: 000303492800207The effects of laser machining process parameters namely, scan speed and frequency on wear performance of AISI H13 hot work tool steel were investigated in this study. The process parameters are combined with wear process factors and the responses of wear tests were evaluated. The results showed that both friction coefficient and wear rate are affected by process parameters. The average friction coefficient and wear rate increased with an increase in frequency at each set of scan speed. Lowest scan speed and highest frequency produced higher surface roughness and rough texture form.Ege UniversityEge University [35MUH08]We are grateful to Laser Mikron Ltd. Sti. company in Izmir-Turkey where laser tests were performed. This work was supported by Ege University under contract no.35MUH08

Tribological behavior of PIII treated AISI 316 L austenitic stainless steel against UHMWPE counterface

The aim of this work was to study the tribological benefits of PIII treated austenitic stainless steel by nitrogen ions and/or C ions in a ringer solution, which simulates the environment of the human body. This was achieved by hardness, wear and friction testing, and atomic force microscopy and XRD studies. The results showed that the samples, both treated and untreated, exhibited virtually no wear from contact with the ultra high molecular weight polyethylene (UHMWPE) pins, however, the pins themselves exhibited wear. The amount of wear of the pins was found to decrease with increasing PIII treatment temperature, but addition of C to the chamber caused some increase the amount of wear on the pins. Although C ions reduced to improve the hardness, friction characteristic was improved by formation of carbon-expanded austenite

The life of WC–Co cutting tools treated by plasma immersion ion implantation

In this study, the tool life of plasma immersion nitrogen-implanted cutting inserts while machining AISI 4140 steel has been investigated. The implantation time was 5 h and the temperature was in the range 320–520 °C. Implantation dose was not, vert, similar2×1018 ions cm−2 for all treatments. Surface topography of the implanted surfaces was obtained from atomic force microscopy. Results of the turning tests are discussed in terms of tool life (flank wear) and surface roughness of the workpieces. The results show that plasma immersion nitrogen implantation increased tool life by about 85%