Tham khảo tài liệu 'friction, lubrication, and wear technology (1997) part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Adhesive Wear Adhesive wear occurs when two surfaces slide against each other with intended motion producing fragments from one surface that adhere to the other Ref 6 . It arises from the strong adhesive forces set up when two materials come into intimate contact. It generally occurs when lubrication is inadequate and results in metal transfer usually called galling. Soft bearing coatings allow the embedding of abrasive particles and also permit deformation for alignment of bearing surfaces. Adequate lubrication is required. Coatings of this type are generally low in cost because they wear in preference to the mating surface Fig. 6a . tai tbl Fig. 6 Cutaway views of thermal spray coated bearings showing areas that exhibit adhesive wear. a Soft bearing material. b Hard bearing material The following performance factors apply to soft bearing coatings Good lubrication must be provided or the wear rate will be excessive The coating must be soft enough to trap the many abrasive particles that will be carried by the lubricant These coatings generally have poor abrasive wear resistance The inherent nature of thermal spray coatings enhances their usefulness as bearing coatings. Pores act as reservoirs for lubricant with reduced particle junctions there is less tendency for adhesive wear Applications and recommended materials for soft bearing coatings are listed in Table 1. Table 1 Thermal spray coatings for friction and wear applications Type of wear Coating material Coating a process Applications Adhesive and abrasive wear Adhesive wear Soft bearing coatings Aluminum bronze OFW EAW OFP PA HVOF Babbitt bearings hydraulic press sleeves thrust bearing shoes piston guides compressor crosshead slippers Tobin bronze OFW EAW Babbitt OFW EAW OFP Tin OFW EAW OFP Hard bearing coatings Mo Ni-Cr-B- Si blend Molybdenum PA OFW EAW PA Bumper crankshafts for punch press sugar cane grinding roll journals antigalling sleeves rudder bearings impeller shafts pinion gear journals piston rings
