SG砂轮磨削钛合金烧伤机理

钛合金以其良好的耐热耐腐蚀性和特别高的比强度在国内外航空航天工业上得到了广泛的应用.针对钛合金在磨削加工过程中极易发生的磨削烧伤问题,采用先进的测试方法,对磨削过程中磨削力、磨削温度、工件表面粗糙度及表面形貌、表面层金相组织及显微硬度等变化规律进行了分析研究.研究结果表明,TC6钛合金在磨削温度超过600℃时即发生烧伤.表面形貌随磨削温度的升高而逐渐恶化.当发生严重烧伤时,工件表面有裂纹产生,其方向大致与磨削方向垂直.工件烧伤时材料表层的金相组织发生变化, α 相颗粒明显粗大,使得钛合金的物理机械性能下降.研究结果为寻求优化的高效、高精度钛合金磨削加工工艺提供理论及实验依据. 

Grinding burn mechanism of Titanium alloys with SG wheels

Titanium alloys have been widely used in aerospace for their excellent heat-resistant, erosiveresistant and especially high strength-to-weight ratio. Grinding burn is apt to occur in the grinding process of titanium alloys. The grinding burn mechanism of titanium alloys was studied on the base of systematical analy- sis of variable characteristics of the grinding force, grinding temperature, surface roughness and topography of ground surface, hardness distribution of surface layer, as well as morphology of surface layer from a metallographic point of view. Some conclusions were given as follows. The grinding burn occurs at the temperature over 600 %. The surface topography deteriorates gradually with elevating grinding temperature. When severe burn appears, some microcracks perpendicular to the grinding direction on the surface of the test-piece are found. With the onset of grinding burn, ot phase particles become coarsening, which deteriorate the mechani- cal properties of titanium alloys obviously. The results provide a theoretical and experimental basis for technical optimization in the grinding of titanium alloys with high efficiency and high quality.