Experimental Research of Wear on the Material Adjustment for HMMWV’s Engine Cylinder

• Main Authors: Fu, Ching-Kai, 傅競凱
• Other Authors: Hou, Kung-Hsu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/18776799126265488178

碩士 === 國防大學中正理工學院 === 兵器系統工程研究所 === 93 === This research is to study the modification technology that can complete maintenance for the cylinders with seriously worn and corroded cylinder walls by installing cylinder sleeves when the High Mobility Multipurpose Wheeled Vehicles (HMMWV) are overhauled in the Automobile Base Department, and to further research the related wears. The experiment methodology is performed in two aspects. One of the two experiment methodologies is to increase carbon (C) and add two alloy elements, copper (Cu) and molybdenum (Mo), to adjust the material characteristics of the FC250 gray cast iron that is used to manufacture the cylinder sleeve. The other is to use the electrodepositing method to electroplate the Ni-P alloy coating and the Ni-P-SiC composite coating on cast iron to conduct surface change, and then to perform wear testing and related testing and analysis. For the cast iron and its adjustment of material characteristics, the experiment results show that the high temperature wear resistance of the alloying cast iron after increasing carbon (C) and adding copper (Cu) and molybdenum (Mo) is better than its normal temperature wear resistance. Also, it is better than the original cast iron material. For the surface change by using the Ni-P based matrix of codeposited layer, under normal temperature and same hardness condition, the Ni-P-SiC composite coating’s best wear resistance value is better than the Ni and Ni-P coating’s. Under high temperature, the wear resistance of the high phosphorous Ni-P coating at 300℃ is better than the wear resistance of the same category Ni-P coating at 200℃. The Ni-P-SiC composite coating with high phosphorous and high SiC has lower wear loss at 300℃, and the wear loss is lower than the same category Ni-P-SiC composite coating at 200℃. The results and analysis of this research show the cast iron material for manufacturing the engine cylinder sleeve can enhance its wear resistance after proper characteristics adjustment of the alloy element and the temperature and timing processing. In addition, by using electroplate of the Ni-P based matrix of codeposited layer to change the surface can strengthen the surface wear resistance of the casting iron.