摘要
注塑模具流道出口工况苛刻,极易发生磨损,导致其形状和尺寸发生变化,对产品的质量和生产效率造成较大影响.基于此,本研究采用激光熔覆技术对注塑模具流道出口进行局部强化,针对强化涂层材料成分的设计、熔覆成形和缺陷控制、组织性能分析、实际工件加工工艺调控等开展研究.结果表明:相比商用耐磨涂层材料,所开发的涂层材料具备优异的熔覆成形和无裂纹缺陷,硬度由强化前基体硬度400H V提升至900H V以上,涂层耐磨性能相对基体提升43倍,摩擦系数由基体的0.635降至0.412,极大改善了模具的耐磨性能;强化涂层内部晶粒细小,主要由马氏体和原位陶瓷碳化物保障其耐磨性,并残留少量奥氏体保障其韧性;通过特殊的路径规划和工艺控制,在注塑模具局部强化中得到成功应用,强化后模具的服役寿命提升3倍以上.
Abstract
The outlet working condition of the injection molding die is harsh.It is very easy to be worn,damaging the outlet shape and size of the flow channel.It has a great impact on the product quality and production efficiency.Therefore,it is urgent to strengthen the outlet of the flow channel.Based on this,the laser cladding technology is used to locally strengthen the outlet of the injection molding die.The composition of the reinforced coating is designed.The cladding appearance and defect is controlled.The microstructure and mechanical property is analyzed.The process control of the actual workpiece processing is studied.Compared with the commercial wear-resistant coating materials,the hardness of the coating materials increased from 400HV to above 900HV.The wear-resistant performance of the coating increased 43 times compared with the matrix.The friction coefficient decreased from 0.635 to 0.412.The wear-resistant performance of the die is greatly improved.The inner grain of the reinforced coating is fine.Its strength and abrasion resistance are mainly guaranteed by martensite and in-situ ceramic carbide.A small amount of austenite is left to guarantee its toughness.Through special path planning and process control,it has been successfully applied in local strengthening of injection molding dies.The service life of the strengthened dies has been increased by more than 3 times.
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