THE EFFECT OF WEAR MECHANISM FOR PLASMA OXIDISED CP TI AND ITS ALLOYS ON TRIBOCORROSION PERFORMANCE

THE EFFECT OF WEAR MECHANISM FOR PLASMA OXIDISED CP TI AND ITS ALLOYS ON TRIBOCORROSION PERFORMANCEAbstract Commercially pure titanium (cp-Ti) and its alloys (Ti6Al4V, Ti45Nb, Ti6Al7Nb etc.) have an important use among biometallic materials. Recently developed alloying techniques and production methods have enabled many different titanium alloys to be used as biomaterials. Although harder and higher corrosion resistance than iron and its alloys, it is used as an invasive implant by applying various surface modifications to improve biodegradability performance. One of these processes is plasma oxidation process. With this process, corrosion resistance can be improved by obtaining more passive surfaces. There are many studies on these performance measurements in the literature. In this study, the effects of wear and corrosion mechanisms on the material in one cycle were investigated. Cp-Ti, Ti6Al4V and Ti45Nb were chosen as base materials. Samples were subjected to plasma oxidation for 600˚C-3 hours. Within the scope of this investigation, the adhesive wear mechanism on oxidized surfaces was compared with different types of abrasives, and its effect on corrosion performance was measured with the tribocorrosion test apparatus. Abrasion tests were carried out with two abrasive balls: tungsten carbide (WC) and silicon nitride (SiN) under 3 N load. Processes were carried out in two different media, dry and simulated body fluid (SBF). Potentiodynamic polarization scans were carried out using the scanning range of -0.28 V - 2 V in the presence of wear tests for tribocorrosion measurements. While abrasive wear mechanism is dominant in untreated samples, adhesive wear is at the forefront in coated samples. The effects that increase the corrosion resistance positively affected the performance of tribocorrosion. The high oxidation resistance of Ti and its alloys increased adhesive wear performance, and because of the higher corrosion resistance of Ti6Al4V and Ti45Nb, which were alloyed from these three material groups, their corrosion performance was higher than Cp-Ti.Keywords: Cp-Ti, Ti6Al4V, Ti45Nb, Plasma oxidation, Tribocorrosion

PREFERENCE OF SOME WALNUT CULTIVARS BY PESTS

Ceviz yetiştiriciliği son yıllarda popülaritesi artan tarımsal üretim dalıdır. Tüm dünyada olduğu gibi ülkemizde de ceviz yetiştiriciliğinde profesyonelliğe geçiş başlamış, kurulan kapama bahçeler ile üretim miktarı ve kaliteyi artırma çabaları hızlanmıştır. Son dönemde ülkemizde tek parça halinde 1.000 dekarın üzerinde birçok bahçe kurulmuş, meyve vereceği gün beklenmekte ve her türlü bakım işlemi yapılmaktadır. Cevizde kaliteyi ve verimi artırmanın yanında, hastalık ve zararlılar açısından da çalışmalar yapılmalı ve ileride büyük sorunlara neden olabilecek etmenler önceden tespit edilmeli ve önlem alınmalıdır. Bu çalışmamızda, 2008 yılında farklı çeşitler (Chandler, Fernor, Kaman 1, Kaman 5, Yalova 1,Yavuz, Şebin, Bilecik) ile kurulmuş kapama ceviz bahçesindeki cevize zarar veren etmenler araştırılmış ve bu etmenlerin popülasyon takibi yapılmıştır. Ağaçlara zarar veren etmenlerin yaprak ve meyve üzerindeki zararları ayrı ayrı incelenerek tespit edilmiş, yaprak üzerinde, kırmızı örümcek (Tetranychus urticae), yaprak biti (Callaphis juglandis), armut kaplanı (Stephanitis pyri) meyve üzerinde ise elma iç kurdu (Cydia pomonella L.) ve kuş zararı olduğu belirlenmiştir. Çalışma sonucunda elma iç kurdu en çok Fernor ve Yavuz'u, Yaprak bitleri en çok Chandler'i, Armut kaplanı en fazla Yavuz'u tercih etmiştir. Kuşların ise kabuğu ince olan çeşitleri yani Chandler ve Kaman 1'i tercih ettiği belirlenmiştirPREFERENCE OF SOME WALNUT CULTIVARS BY PESTS Cultivation of walnut is a agricultural production branch that has become more popular recently. Similar to other countries in the world, cultivation of walnut has begin to pass through professionalism in our country and with close gardens, efforts of raising an amount of production and quality have been accelerated. In the last period, over 1.000 decare many gardens has been built up massively in our country. The period of harvest is expected and every overhaul is being done. As well as increasing of walnut quality and yield, studies in disease and pests should be done and factors that will lead to big problems should be determined before and should take precautions. In this study, in 2008, factors that damage walnuts in the close walnut garden which has been built up with different types (Chandler, Fernor, Kaman 1, Kaman 5, Yalova 1, Yavuz, Şebin, Bilecik) were investigated and population tracking of these factors was done. Factors that damage trees and harms on leaf and fruit have been determined by investigating respectively, it is determined that there are red spider (Tetranychus urticae), aphid (Callaphis junglandis), codling moth (Cydia pomonella L.), less of bird on fruit. In the study results, codling moth preferred Fernor and Yavuz, aphids preferred Chandler, Stephanitis pyri preferred Yavuz mostly, birds preffer types that has slim crust like Chandler and Kaman

PREFERENCE OF SOME WALNUT CULTIVARS BY PESTS

Ceviz yetiştiriciliği son yıllarda popülaritesi artan tarımsal üretim dalıdır. Tüm dünyada olduğu gibi ülkemizde de ceviz yetiştiriciliğinde profesyonelliğe geçiş başlamış, kurulan kapama bahçeler ile üretim miktarı ve kaliteyi artırma çabaları hızlanmıştır. Son dönemde ülkemizde tek parça halinde 1.000 dekarın üzerinde birçok bahçe kurulmuş, meyve vereceği gün beklenmekte ve her türlü bakım işlemi yapılmaktadır. Cevizde kaliteyi ve verimi artırmanın yanında, hastalık ve zararlılar açısından da çalışmalar yapılmalı ve ileride büyük sorunlara neden olabilecek etmenler önceden tespit edilmeli ve önlem alınmalıdır. Bu çalışmamızda, 2008 yılında farklı çeşitler (Chandler, Fernor, Kaman 1, Kaman 5, Yalova 1,Yavuz, Şebin, Bilecik) ile kurulmuş kapama ceviz bahçesindeki cevize zarar veren etmenler araştırılmış ve bu etmenlerin popülasyon takibi yapılmıştır. Ağaçlara zarar veren etmenlerin yaprak ve meyve üzerindeki zararları ayrı ayrı incelenerek tespit edilmiş, yaprak üzerinde, kırmızı örümcek (Tetranychus urticae), yaprak biti (Callaphis juglandis), armut kaplanı (Stephanitis pyri) meyve üzerinde ise elma iç kurdu (Cydia pomonella L.) ve kuş zararı olduğu belirlenmiştir. Çalışma sonucunda elma iç kurdu en çok Fernor ve Yavuz'u, Yaprak bitleri en çok Chandler'i, Armut kaplanı en fazla Yavuz'u tercih etmiştir. Kuşların ise kabuğu ince olan çeşitleri yani Chandler ve Kaman 1'i tercih ettiği belirlenmiştirPREFERENCE OF SOME WALNUT CULTIVARS BY PESTS Cultivation of walnut is a agricultural production branch that has become more popular recently. Similar to other countries in the world, cultivation of walnut has begin to pass through professionalism in our country and with close gardens, efforts of raising an amount of production and quality have been accelerated. In the last period, over 1.000 decare many gardens has been built up massively in our country. The period of harvest is expected and every overhaul is being done. As well as increasing of walnut quality and yield, studies in disease and pests should be done and factors that will lead to big problems should be determined before and should take precautions. In this study, in 2008, factors that damage walnuts in the close walnut garden which has been built up with different types (Chandler, Fernor, Kaman 1, Kaman 5, Yalova 1, Yavuz, Şebin, Bilecik) were investigated and population tracking of these factors was done. Factors that damage trees and harms on leaf and fruit have been determined by investigating respectively, it is determined that there are red spider (Tetranychus urticae), aphid (Callaphis junglandis), codling moth (Cydia pomonella L.), less of bird on fruit. In the study results, codling moth preferred Fernor and Yavuz, aphids preferred Chandler, Stephanitis pyri preferred Yavuz mostly, birds preffer types that has slim crust like Chandler and Kaman