包埋深度的確定
(南京航空航天大學(xué) 機(jī)電學(xué)院，南京 210016)
摘 要: 以Ag-Cu-Ti合金為釬料在真空爐中實(shí)現(xiàn)了CBN磨粒與45鋼基體的釬焊連接，運(yùn)用紅外光譜儀測(cè)試了釬焊磨粒內(nèi)部的殘余應(yīng)力，分析了最大殘余拉應(yīng)力對(duì)磨粒強(qiáng)度的影響，據(jù)此優(yōu)選了釬焊CBN砂輪工作面上磨粒的包埋深度。結(jié)果表明：當(dāng)包埋深度不同時(shí)，盡管釬焊磨粒內(nèi)部的殘余應(yīng)力分布差異較大，但最大殘余拉應(yīng)力始終位于磨粒與釬料頂層截面的邊緣位置，并且最大殘余拉應(yīng)力與包埋深度不存在線性關(guān)系；為提高釬焊CBN磨粒強(qiáng)度和確保砂輪容屑空間，磨粒包埋深度應(yīng)控制在其自身高度的30%~40%之間。
關(guān)鍵字: CBN磨粒；釬料層；單層釬焊砂輪；包埋深度；殘余應(yīng)力
on working surface of single-layer brazed CBN grinding wheel
XIAO Bing, ZHOU Lai-shui
（College of Mechanical and Electrical Engineering,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China）
Abstract:The joining of CBN abrasive grain and 0.45%C steel matrix was realized using Ag-Cu-Ti alloy as filler metal in the vacuum furnace. The residual stresses of the brazed CBN grains were measured by means of FTIR spectra. The influence of the maximum tensile stress on the grain strength was analyzed, and the embedding depth of grains on the working surface of the brazed single-layer grinding wheels was accordingly determined. The result shows that, though remarkable difference of stress distribution occurs in the brazed grains with different embedding depths, the maximum tensile stress always exists in the margin region of the section plane between CBN grain and filler top. Moreover, the maximum tensile stress is not influenced linearly by the embedding depth. In order to ensure the strength of the brazed grains and the enough space for holding chips, 30%−40% of the whole height of abrasive grain is the rational embedding depth for CBN grains.
Key words: CBN abrasive grain; filler metal layer; singer-layer brazed grinding wheel; embedding depth; residual stress
