Aluminum alloy has been gradually utilized in cylinder block instead of ferrous casting material for weight reduction in automobile industry these days. In order to acquire more weight reduction, a new liner-less technology - without cast iron liner used - is putting into practice in the fields of aluminum cylinder block and the target is for diesel engine. However, diesel fuel's impurity "sulfur" element and corrosive attack risk, such as sulfuric acid generated to the surface of liner is higher than gasoline fuel. Because of such disadvantage, wear and corrosion resistances applied to the inner cylinder-bore are required in order to achieve this liner-less aluminum cylinder block. This research is intended to accomplish both wear and corrosion performances using plasma thermal spray technology and to verify the feasibility of application to actual engine bore. A newly-developed ferrous powder (Fe-C-Ni-Cr-Cu-V-B alloy) revealed extremely excellent corrosion and wear resistances, compared with currently used bulk casting materials such as Fe-C-Si-B alloy and Fe-C-Si-Mo-B alloy for cylinder liner. For the last time, the new ferrous alloy powder was applied to actual engine bore by using Rota-Plasma spray coating. The experimental results with engine bore presented potential equivalent to current engine bore.
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