Authors: Faisal Farooq Khan Gyuyeol Bae Kicheol Kang Hyuntaek Na Junghwan Kim Taeho Jeong Changhee Lee
Publish Date: 2010/12/30
Volume: 20, Issue: 5, Pages: 1022-1034
Abstract
Soldering and erosion are two of the biggest serious problems faced in the diecasting industries Cermet coatings utilized by highvelocity oxyfuel HVOF spray technology have been developed in an attempt to overcome these problems MoBbased cermet feedstock powders MoB/NiCr and MoB/CoCr were deposited on SKD61 AISI H13 substrates used as a preferred die mold material Microstructural and mechanical properties of the coatings have been characterized by scanning electron microscopy xray diffraction Romulus bond strength test and Vickers microhardness test The durability of these coatings on cylindrical specimens against soldering also has been investigated by immersing in molten aluminum alloy ADC12 for 25 h at 670 °C and subsequently compared with that of NiCr and CoMoCr coatings Both types of MoBbased cermet coatings have shown high soldering resistance as negligible intermetallic formation occurred during the immersion test This result is attributed to the existence of multiple inert borides in the coatings The coatings also showed excellent mechanical properties MoB/NiCr in particular showed higher bond strength hardness and wear resistance than MoB/CoCr This suggests that MoB/NiCr will show higher durability than MoB/CoCr NiCr and CoMoCr during high pressure diecasting of aluminum alloysThis study was supported by Hyundai Motors Ltd Republic of Korea as well as Korea Science and Engineering Foundation KOSEF Grant funded by the Korean Government MOST No 200602289 This research study was also sponsored by the Higher Education Commission HEC Government of Pakistan under the MS Level Training in Korean Universities/Industry scholarship program bearing GRE type Test Roll Number
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