: INFLUENCE OF SOME ADDITIVES ON PROPERTIES OF GREASES

This work aims to study the influence of some additives on the properties of soap greases, such as lithium, calcium, sodium, lithium-calcium by adding first: additives including graphite,molybdenum disulfide, carbon black, corrosion inhibiter and extreme pressure, second: base stock oils 40, 60, 150.Various additives have been added to greases to obtain the best percentages that improve the properties of grease such as load carrying, wear resistance, corrosion resistance,drop point and penetration.The result showed the best weight percentages to all types of grease which give good properties are 1.5% extreme pressure additive, 3% graphite, 1% molybdenum disulfide, 2.5% carbon black.On the other hand, the best weight percentage for corrosion inhibiter is 1% to lithium-calcium grease, 2% to lithium grease and
3% to sodium grease. It was concluded that there is no need to add corrosion inhibiter to calcium grease.For adding stock oils (40, 60, 150) to greases, a decrease in grease properties has been noticed when adding 20% of base stock oil 40,30% of base stock oil 60, and no significant change being observed of base stock oil 150.