Ön sertleştirilmiş Toolox 44 ve Nimax kalıp çeliklerinin işlenebilirliği üzerine deneysel çalışma

Bu çalışmada, kalıp çelikleri arasında yer alan Nimax ve Toolox 44 malzemelerinin frezeleme işleminde işlenebilirliği deneysel olarak araştırılmıştır. Kesme deneyleri, üçer farklı kesme hızı (50-70-90 m/dak), ilerleme (0,04-0,08-0,12 mm/diş) ve sabit kesme derinliği (1,5 mm) kullanılarak CVD-AlCrN kaplamalı karbür parmak freze ile gerçekleştirilmiştir. Deneyler sonucunda, aynı koşullar altında Toolox 44’ün işlenmesinde Nimax’a göre daha fazla kesme kuvveti ve yüzey pürüzlülüğünün oluştuğu gözlenmiştir. Nimax malzemenin işlenmesinde optimum kesme parametreleri yüksek kesme hızı ve düşük ilerleme (V:90 m/dak, f:0,04 mm/diş) iken, Toolox 44’te ise düşük kesme hızı ve ilerleme (V:50 m/dak, f:0,04 mm/diş) olarak tespit edilmiştir. Kesme hızının 50 m/dak’tan 90 m/dak’a artması ile Toolox 44’te kesme kuvveti 0,04-0,08 ve 0,12 mm/diş ilerleme değerlerinde sırasıyla %140,139; %11,286 ve %15,179 artarken, Nimax’ta ise %3,221; %2,974 ve %5,062 azaldığı gözlenmiştir. Aynı şekilde kesme hızının artması ile Toolox 44’te yüzey pürüzlülüğü 0,04-0,08 ve 0,12 mm/diş ilerleme değerlerinde sırasıyla %78,162; %34,721 ve %8,878 artarken, Nimax’ta ise %3,515; %30,027 ve %9,806 azaldığı belirlenmiştir. İşlenmiş yüzey altı görüntülerine göre Nimax’ta işlenmiş yüzeyde ilerlemenin artması ile çukur oluşurken, Toolox 44’te ise deforme olmuş ve ısıdan etkilenmiş tabaka meydana gelmiştir. Ayrıca, aynı ilerleme parametrelerinde Toolox 44’ün işlenmiş yüzeylerinde Nimax’a göre daha fazla ilerleme izlerinin oluştuğu ve bunun da yüzey pürüzlülüğünü arttırdığı tespit edilmiştir.

Anahtar Kelimeler:

İşlenebilirlik, Frezeleme, Nimax, Toolox 44, Kesme kuvveti, Yüzey pürüzlülüğü

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