Yazar "Gokkaya, Hasan" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    Investigation Of Electroerosion Machining Performance Of Metal Matrix Composite Materials Produced Using Stir And Indirect Squeeze Method
    (World Scientific Publ Co Pte Ltd, 2023) Ugur, Abdullah; Nas, Engin; Gokkaya, Hasan
    In this study, metal matrix composite (MMC) materials were made with an aluminum matrix (AA7075 alloy) and reinforcement silicon carbide (SiC) elements using molten metal stir and indirect squeeze casting. SiC was used as a reinforcing element in the making of MMC material in different amounts (10%, 14%, and 18%) by mass. Electro Discharge Machining (EDM), cut depth (0.5 mm), three different pulse-on times, three different discharge current values, and a fixed pulse-off time (20 s) were used to machine MMC materials. The effects of machining parameters on machining time, average surface roughness, hole diameter, and material wear difference after machining were studied. As a result of the study, the composite material with 75 mu s pulse-on time, 6A current value, and 10% reinforcement element had the lowest machining time, the largest hole diameter, and the smoothest average surface. These machining parameters and materials also had the shortest machining time (5 min). Based on the signal-to-noise ratios, the best parameters for average surface roughness, hole diameter, Processing time, and material wear amount (MMC, discharge current value, and impact time) were found to be L2L1L1, L3L1L1, L1L3L3, and L1L1L2, respectively. Based on the ANOVA results, the R2 values for the average surface roughness, hole diameter, machining time, and material wear loss value were 99.3%, 98.7%, 77.8%, and 97.3%, respectively.
  • Küçük Resim
    Öğe
    Investigation of the machinability of SiC reinforced MMC materials produced by molten metal stirring and conventional casting technique in die-sinking electrical discharge machine
    (Pergamon-Elsevier Science Ltd, 2020) Ugur, Abdullah; Nas, Engin; Gokkaya, Hasan
    In this study, MMC materials were produced by stir casting method using AA7075 alloy matrix and silicon carbide (SiC) as reinforcement elements in order to investigate the effect of die-sinking electric discharge machining (EDM) process parameters for various weight percentage reinforcement (10% 14% and 18%) used MMC. EDM with three different pulse-on time (Time on) (25, 50 &75 mu s) and discharge current value (2, 4 & 6 Amperes) and at constant dwell time (20 mu s) and depth of cut (0.5 mm). After machining process, the effects of process parameters on processing time, average surface roughness, hole diameter and the weight loss were investigated. As a result of the study, highest values, the lowest values of processing time, hole diameter and average surface roughness were obtained for various weight percentage reinforcement MMC respectively. Ideal MMC, discharge current value and time-on duration for average surface roughness, hole diameter, processing time and material wear loss according to signal to noise ratio were determined. According to ANOVA results, R-2 values for the average surface roughness, hole diameter, processing time and material wear loss were calculated as 89.55%, 98.46%, 89.85% and 24.06% respectively.
  • Küçük Resim
    Öğe
    Taguchi optimization of surface roughness in the turning of Hastelloy C22 super alloy using cryogenically treated ceramic inserts
    (Sage Publications Ltd, 2020) Akincioglu, Sitki; Gokkaya, Hasan; Akincioglu, Gulsah; Karatas, Meltem A.
    Cryogenic treatment has been used in recent years to improve the performance of cutting tools. This study evaluated the machinability of a nickel-molybdenum-based super alloy using cryogenically treated (-80 celcius and -145 celcius) ceramic inserts under dry turning conditions. Three cutting speeds (350, 400, and 450 m/min), three feed rates (0.1, 0.2, and 0.3 mm/rev), and a 1-mm fixed cutting depth were used in the turning tests. Experiments were conducted using the Taguchi orthogonal array L(27)design. The factors affecting the surface roughness (Ra) were determined via analysis of variance. The effect of cryogenic treatment type (shallow and deep), cutting speed, and feed rate on surface roughness was investigated. Results of the analysis determined that the feed rate was the major parameter that affected surface roughness and that the deep cryogenic treatment was more effective. The regression analysis confirmed that the experimental results and the predicted values were within the 95% confidence interval. The most effective parameter affecting the surface roughness was feed rate at a contribution of 57.9%. The contribution of the cutting tool type to the surface roughness was 28.5%. The results obtained showed that the surface roughness can be optimized for turning the Hastelloy c22 super alloy with the Taguchi method.