摘要
通过添加造孔剂碳酸氢钠颗粒至超硬磨料砂轮工作层,制备兼具高锋利度、大容屑空间、长寿命的新型CBN砂轮,旨在解决钛合金材料高效磨削过程中,加工效率低、工件表面易烧伤、砂轮磨损严重等问题。通过开展钛合金干式磨削试验,对比分析绿色碳化硅砂轮和新型多孔CBN砂轮在不同磨削用量条件下的材料去除率、磨削温度、砂轮及工件表面形貌。研究结果表明:结合金属结合剂对CBN磨粒浸润效果和节块弯曲强度方面分析,砂轮中石墨质量分数优化为10%。相同磨削用量条件下,多孔CBN砂轮最高磨削温度为250℃,是碳化硅砂轮的41.6%。此外,多孔CBN砂轮的材料去除率和磨削比分别为碳化硅砂轮的4倍和2倍,且表面粗糙度更低。因此,采用新型多孔CBN砂轮磨削钛合金,能够达到提升磨削加工效率,改善磨削加工表面质量,增大砂轮使用寿命的目的。
Porous metal-bonded cubic boron nitride(CBN) grinding wheels are fabricated by employing ammonium hydrogen carbonate(NH4HCO3) as pore-forming agents to avoid workpiece burn, improve ground surface quality and service life during grinding Ti-6Al-4V titanium alloys. The graphite particle concentrations are optimised with the flexural strength and interface morphology between the metallic matrix and grains. The grinding performance, including grinding temperature, material removal rate, grinding ratio, grains wear and ground surface quality of the porous CBN wheels and silicon-carbide abrasive wheels is evaluated during grinding Ti-6Al-4V titanium alloys without cooling lubricants. Results indicate that porous CBN wheels with 10%(mass fraction) graphite particles are optimized in terms of the wettability between the metallic matrix and abrasive grains as well as the flexural strength. In addition, porous CBN wheels exhibit high porosity and promising comprehensive grinding performance. In comparison with the silicon-carbide abrasive wheels, a lower grinding temperature(approximate 250℃) and better ground surface quality can be achieved by porous CBN wheels. Moreover, the material removal rate and grinding ratio of porous CBN wheels reach about 4 and 2 times than that of the silicon-carbide abrasive wheels under the same conditions.
作者
杨薇
温学兵
肖红
赵彪
丁文锋
YANG Wei;WEN Xuebing;XIAO Hong;ZHAO Biao;DING Wenfeng(Naval Equipment Department,Xi’an 710021,China;AECC Xi’an Aero Engine Co.,Ltd.,Xi’an 710021,China;College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《航空制造技术》
2019年第20期64-69,82,共7页
Aeronautical Manufacturing Technology
关键词
钛合金
多孔CBN砂轮
磨削温度
材料去除率
表面粗糙度
Ti-6Al-4V titanium alloy
Porous CBN wheel
Grinding temperature
Material removal rate
Surface roughness
作者简介
通讯作者:丁文锋,博士,教授,博士研究生导师,主要研究方向为超硬磨料工具技术、高速超高速磨削加工技术、难加工材料高效精密加工技术,E-mail:dingwf2000@vip.163.com。
