Research On Friction Wear Of Cast Iron Processed By Laser Bionic Coupling Technique After Thermal Fatigue

Research on friction wear of cast iron processed by laser bionic coupling technique after thermal fatigueGrey cast iron is widely used as the material of brake drum. Its wearability have attract the attention of researchers. Frictions wear between mechanical parts in engineering causes enormous economic losses to national economy. Material thermal fatigue and wear resistance can be improved by changing the material surface performance. From the mysterious nature we got inspiration, through animals and plants form their bodies in the most harmonious way to survive in evolution and natural selection. The elytra of dung beetle, shells etc. have biological soft and hard structure on surface which build up the non-smooth unit with better wearability. By optimization the body surface shape, size and structure of biological surface coupling, they present a better wear resistant.Under this coupling theory, by using the technology of laser processing on grey cast iron material, bionic coupling unit was obtained. The friction wear of the sample after the thermal fatigue was studied. The working condition of the brake drum includes fatigue and wear, so studying on the wear after the fatigue can make a more realistic result. After applying the wear tests of gray cast iron on different shapes, load and different times of fatigue ect. , the results can be summarized as below:1. With the increase of times of thermal fatigue, the wear loss of samples raises. The least of wear loss is the samples which don't do the thermal fatigue, the most of wear loss is the samples which do 4000 times thermal fatigue. The wear loss of the samples which don't do the thermal fatigue is lower about 26% than the wear loss of samples after 1000 times thermal fatigue, the wear loss of the samples which don't do the thermal fatigue is lower about 28% than the wear loss of samples after 2000 times thermal fatigue, the wear loss of the samples which don't do the thermal fatigue is lower about 51% than the wear loss of samples after 3000 times thermal fatigue, the wear loss of the samples which don't do the thermal fatigue is lower about 52% than the wear loss of samples after 4000 times thermal fatigue. The wear loss of samples after 3000 times thermal fatigue has surged greater phenomenon than the wear loss of samples after 2000 times thermal fatigue. The wear loss of samples after 4000 times thermal fatigue is similar with the wear loss of samples after 3000 times thermal fatigue.2. The wear resistance is different under the condition of the different times of thermal fatigue and the different shapes of the bionic coupling unit. After 1000 times, 2000 times, 3000times and 4000 times thermal fatigue, the wear loss of the grid shape of the bionic coupling unit is lower about 97% than the untreated samples, the wear loss of the twill shape of the bionic coupling unit is lower about 95% than the untreated samples, the wear loss of the cross grain and stripe shape of the bionic coupling unit is lower about 93% than the untreated samples.3. The material performance of the samples with the bionic coupling unit of grey cast iron which process by laser after the thermal fatigue change, the strength and hardness decline, the organization appears the crystal disintegration, the grain boundaries crisscross after the crystal disintegration and expand into cracks.4. Adhesion wear and particle wear are both observed on the wear surface. The surface morphology of samples appears trace of scratching and plowing. After the thermal fatigue, the degree of the crystal disintegration in the unit is less than the base. The exist of the bionic coupling unit enhances the wear resistance, the wear loss reduce.