No abstract

Bu çalışmada, farklı matkap geometrileri ve kesme parametrelerinin delme performansı üzerine etkileri sistematik bir şekilde incelenmiştir. Farklı geometrilere sahip dört tip matkap kullanılarak itme kuvveti, moment, yüzey pürüzlülüğü ve geometrik toleranstan sapma değerleri ölçülmüştür. Deneysel çalışmalarda ticari olarak temin edilebilen yaygın iki takım geometrisi ile özgün iki kanal geometrisinin performansları test edilmiştir. Delme operasyonu, 10 mm çapında, iki ağızlı, helisel, yekpare sementit karbür matkaplar kullanılarak GGG 50 malzemesi üzerinde gerçekleştirilmiştir. Deney deseni için matkabın geometrik formu, kesme hızı ve ilerleme miktarı olmak üzere dörder seviyeli üç farklı kontrol faktörü ile bir Taguchi Deney Tasarımı oluşturulmuştur. Deney sonuçlarının değerlendirilmesinde Taguchi S/N analizi ve elde edilen verilerin işlendiği grafikler kullanılmıştır. Anova analizi yardımıyla da deney parametrelerinin deney sonuçları üzerindeki önemi ve etki oranları bulunmuştur. Deneysel sonuçlar değerlendirilerek optimum geometri ve optimum işleme şartları belirlenmiştir. Taguchi Sinyal-Gürültü analizinde "en küçük en iyidir" yaklaşımıyla değerlendirilen sonuçlara göre; ilerleme kuvveti, giriş-çıkış yüzey pürüzlülüğü, dairesellikten sapma ve diklikten sapma açısından özgün olarak geliştirilen 4 numaralı takım geometrisi diğer geometrilere üstünlük sağlarken, ilerlemenin en düşük olduğu (0,15 mm/dev.) ve kesme hızının en yüksek olduğu (110-120 m/dak.) kesme parametreleri ise kontrol faktörlerinin optimum seviyeleri olarak belirlenmiştir.

Today, dry hard turning is widely used in the processing of hardened steel due to its advantages such as low cost, high machining efficiency and green environmental protection. In this study, hard turning tests were carried out under dry cutting conditions on hardened DIN 1.2367 (55 HRC) steel material. The effect of the cutting parameters (three different cutting speeds, three feed rates and three cutting depths) on the power consumption and sound level values was investigated.

In this study, the effect of cutting parameters on the surface roughness of hard turning DIN 1.2367 (55 HRC) steel material was investigated. Three different cutting speeds, feed rates and cut of depths were used in experiments conducted under dry cutting conditions. It was seen that the most effective cutting parameter in the surface roughness value was the feed rate. In addition, a mathematical model was created to estimate the surface roughness. Figure A. Surface roughness main effect plotsPurpose: In this study; The effect of cutting parameters on the surface roughness was examined and DIN 1.2367 steel was used as the work piece material. Tool steel 1.2367 is a hot work steel with high wear resistance and heat resistance. This material is often used in large pressure die casting production.Theory and Methods: In this study, to examine the hard turning process, DIN 1.2367 material was cooled suddenly in oil after being heated at 900 ℃ for 2 hours to reach a hardness value of 55 HRC by heat treatment. After this process, the steel material has reached a very high hardness value. But the fragility of the material has increased. Tempering has been used to reduce the brittleness of the material. In order to remove the stresses in the cooled material, it was heated at 300 ℃ for 1 hour and cooled in air.Results: Nine additional tests were conducted to observe the effects of the coolant only. Thus, processing time and cost were limited. There appears to be no noticeable change in surface roughness due to the use of coolant. The reason for this can be shown as the temperature does not increase with the CBN tips used in the experiments. The cutting parameter that most affects the surface roughness is the feed rate. It has been determined that as the amount of advance increases, the surface roughness increases. It is known that the feed rate has a significant effect in reducing the surface roughness. Conclusion:In this study, characterization study has been done for DIN 1.2367 steel material and detailed information about the mechanical properties of the material was obtained. According to the results obtained in the experimental studies; It has been observed that surface quality can be obtained by using cutting tools with suitable machine tool and optimum cutting parameters suitable for hard turning process.

In this experimental study, maximum torsion shear stresses occurring on the hallow aluminum shaft under various small torsion loads were measured with strain gauge, data acquisition cards and computer. Special software was developed to measure maximum strain and stress on the thin aluminum hollow shaft. Stress values occurring on the aluminum hallow shaft under various small loads were measured with strain gauge and those strain values were transmitted to computer directly with data acquisition cards. Using the strain, the load and other constant values of the material (Torsion stress, outside and inside diameters of shaft, length of shaft, shear stress modulus, applied torque loads, twist angle of shaft etc) the stress values occurring on the hallow shaft are calculated by computer program and the stress-strain graph is drawn on the computer screen automatically [Refer to table1 Fig. 2,3,4 ,5 and . In this experimental study, the theoretical knowledge given in the books and experiment results obtained under laboratory conditions were compared with each other. The obtained results were almost same. Similar experimental application could be used for real applications in car industry and mobile machines [.