本文選題：陶瓷結(jié)合劑　切入點(diǎn)：金剛石砂輪　出處：《鄭州大學(xué)》2017年碩士論文

【摘要】：陶瓷結(jié)合劑金剛石砂輪具有強(qiáng)度高、加工效率高、加工精度高、形狀保持性好、使用壽命長(zhǎng)等優(yōu)點(diǎn)而被廣泛地應(yīng)用于金剛石復(fù)合片、硬質(zhì)合金、結(jié)構(gòu)陶瓷、寶石等高硬脆性材料的切削和磨削加工生產(chǎn)中。本文以降低金剛石砂輪結(jié)合劑的熱膨脹系數(shù)、燒結(jié)溫度、提高其機(jī)械強(qiáng)度為目的,設(shè)計(jì)了以SiO_2-Al_2O_3-B_2O_3-Na_2O系統(tǒng)玻璃為基礎(chǔ)的陶瓷結(jié)合劑。采用高溫熔融法制備出陶瓷結(jié)合劑。分別研究了Na_2O、Li_2O和ZnO對(duì)陶瓷結(jié)合劑以及金剛石砂輪塊結(jié)構(gòu)與性能的影響規(guī)律。采用高能球磨對(duì)陶瓷結(jié)合劑進(jìn)一步破碎,研究了高能球磨時(shí)間對(duì)陶瓷結(jié)合劑粒度的影響及其對(duì)結(jié)合劑的結(jié)晶溫度和抗彎強(qiáng)度的影響。通過(guò)XRD和FTIR研究分析了陶瓷結(jié)合劑的相組成和成分;采用熱膨脹儀、維氏硬度儀、電子萬(wàn)能試驗(yàn)機(jī)分別測(cè)試結(jié)合劑及金剛石砂輪樣品的熱膨脹系數(shù)、硬度和強(qiáng)度;采用SEM觀察陶瓷結(jié)合劑燒結(jié)體的微觀結(jié)構(gòu)和金剛石磨粒與結(jié)合劑界面結(jié)合特征;采用激光粒度分析儀測(cè)試高能球磨后陶瓷結(jié)合劑的粒度,采用DSC和XRD測(cè)試分析陶瓷結(jié)合劑的結(jié)晶溫度和不同燒結(jié)溫度的晶相組成。研究結(jié)果表明:(1)通過(guò)研究氧化鈉含量對(duì)陶瓷結(jié)合劑性能的影響規(guī)律發(fā)現(xiàn):隨著Na_2O含量的升高,SiO_2-Al_2O_3-B_2O_3-Na_2O系陶瓷結(jié)合劑的燒結(jié)溫度降低,當(dāng)Na_2O含量達(dá)到12.31wt.%時(shí),陶瓷結(jié)合劑具有最低的燒結(jié)溫度。采用Na_2O含量為9.31wt.%的結(jié)合劑與230-270目金剛石混合制備出150濃度的金剛石砂輪試條,在680℃燒結(jié)的砂輪樣品的抗彎強(qiáng)度最高,其值達(dá)到了53.5 MPa,此時(shí)該結(jié)合劑的熱膨脹系數(shù)為10.3×10-6/℃。(2)通過(guò)調(diào)節(jié)Li_2O和ZnO的比例,可以有效地降低陶瓷結(jié)合劑的燒結(jié)溫度,并提高結(jié)合劑的抗彎強(qiáng)度,當(dāng)在Li_2O和ZnO的比例為4:1時(shí),所合成的結(jié)合劑與230-270目金剛石混合制備出150濃度的金剛石砂輪試條,在580℃燒結(jié)所得的金剛石砂輪試塊的抗彎強(qiáng)度達(dá)到了66.4 MPa,此時(shí)該結(jié)合劑的熱膨脹系數(shù)約為9.5×10-6/℃。(3)通過(guò)高能球磨的方法可以有效地降低陶瓷結(jié)合劑粉體的粒度,高能球磨75 min后,得到的粉體粒徑為358 nm,其結(jié)晶溫度比原始粉體的結(jié)晶溫度降低了約50℃,高溫?zé)伤纬傻木w均為β-鋰輝石晶體,并且球磨后得到的超細(xì)粉體在850℃溫度燒結(jié)后,其抗彎強(qiáng)度達(dá)到61.67 MPa,比沒(méi)有經(jīng)過(guò)高能球磨的原始粉體燒結(jié)后樣品的強(qiáng)度提升了近40%。通過(guò)進(jìn)一步調(diào)節(jié)結(jié)合劑的配方,使其結(jié)晶溫度降低至696℃,熱膨脹系數(shù)降至4.6×10-6/℃,抗彎強(qiáng)度提高至105MPa,金剛石砂輪試樣的抗彎強(qiáng)度達(dá)到了76.6 MPa。
[Abstract]:Ceramic bond diamond grinding wheel has been widely used in diamond composite, cemented carbide and structural ceramics because of its advantages such as high strength, high processing efficiency, high machining precision, good shape retention, long service life, etc. The purpose of this paper is to reduce the thermal expansion coefficient of diamond wheel bond, sintering temperature and improve its mechanical strength in cutting and grinding of hard brittle materials such as precious stones. Ceramic binders based on glass in SiO_2-Al_2O_3-B_2O_3-Na_2O system were designed. Ceramic binders were prepared by high temperature melting method. The effects of Na _ 2O _ 2 Li _ 2O and ZnO on the structure and properties of ceramic binders and diamond wheel blocks were studied respectively. High energy ball milling further crushing of ceramic binders, The effect of high energy ball milling time on the particle size of ceramic binder and its effect on the crystallization temperature and bending strength of the binder were studied. The phase composition and composition of the ceramic bond were analyzed by XRD and FTIR. The thermal expansion coefficient, hardness and strength of the binder and diamond wheel samples were measured by electronic universal testing machine, the microstructure of ceramic bond sintered body and the interfacial bonding characteristics of diamond abrasive particles and binder were observed by SEM. The particle size of ceramic bond after high energy ball milling was measured by laser particle size analyzer. The crystallization temperature of ceramic binder and the crystal phase composition of different sintering temperature were analyzed by DSC and XRD. The results showed that the effect of sodium oxide content on the properties of ceramic bond was studied. Increasing the sintering temperature of the SiO2-Al2O3-B2O3-Al2O3-Na2O-based ceramic binders, When the content of Na_2O is 12.31 wt.%, the sintering temperature of the ceramic bond is the lowest. The 150 concentration diamond grinding wheel test strip is prepared by mixing the binder with 230-270 mesh diamond with 9.31 wt.% Na_2O content. The bending strength of the grinding wheel sample sintered at 680 鈩，

本文編號(hào)：1667247