CN108191426A - 一种中温烧结高q值微波介质材料 - Google Patents

一种中温烧结高q值微波介质材料 Download PDF

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CN108191426A
CN108191426A CN201810043801.4A CN201810043801A CN108191426A CN 108191426 A CN108191426 A CN 108191426A CN 201810043801 A CN201810043801 A CN 201810043801A CN 108191426 A CN108191426 A CN 108191426A
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李玲霞
杜明昆
于仕辉
孙正
乔坚栗
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Abstract

本发明公开了一种中温烧结高Q值微波介质材料,目标合成物表达式为Li2TiO3‑x w.t.%MgF2,其中x=2~8。先将Li2CO3和TiO2按化学计量式Li2TiO3进行配料,经球磨、烘干、过筛,于700~900℃预烧,再外加质量百分比含量为2~8%的MgF2,然后进行造粒,再压力制成生坯,生坯于1000℃‑1200℃烧结,制成高Q值Li2TiO3基微波介质材料。本发明实现了中温烧结(<1200℃),Qf值高达到123,730GHz~158,963GHz,制备工艺简单,其制品具有广泛的应用前景。

Description

一种中温烧结高Q值微波介质材料
技术领域
本发明属于一种以成分为特征的陶瓷组合物,特别涉及一种新型中温烧结高Q值微波介质材料及其制备方法
背景技术
微波介质材料可用于制作微波基板、谐振器、滤波器和贴片天线等微波电路中的关键组件,随着无线通信技术的不断发展,对原料成本低廉的高Q值微波介质材料的需求日益增长。对稳频用的谐振器来说,高Q值可以提高频率控制精度,抑制回路中的电子噪声:对滤波器来说,高Q值可以提高通带边缘信号频率相应陡度,提高频带的利用率,因此,高Q值微波介质材料在现代无线应用中必不可少。尽管传统的高Q值复合钙钛矿介质材料如Ba(Mg1/3Ta2/3)O3(BMT)和Ba(Zn1/3Ta2/3)O3(BZT)被广泛研究,但高的烧结温度(>1400℃)、苛刻的制备条件、昂贵的五氧化二钽价格限制了其在微波/毫米波领域的发展。
最近有研究表明,具有岩盐结构的锂基Li2TiO3微波介质材料在毫米波段具有优异的微波介电性能(εr~22.14、Qf~63,525GHz,τf~+20.3ppm/℃),原料相对便宜,制备工艺简单易行,但在(002)面易出现解理现象,表面存在微裂纹,严重影响了Li2TiO3的Qf值,导致其在实际应用中不能满足基站的要求,且烧结温度相对较高(~1300℃)。因此,提高Li2TiO3的Qf值,同时降低其烧结温度,成为目前亟待解决的问题。
微波介质材料可用于制作微波基板、谐振器、滤波器和贴片天线等微波电路中的关键组件,随着无线通信技术的不断发展,对原料成本低廉的高Q值微波介质材料的需求日益增长。对稳频用的谐振器来说,高Q值可以提高频率控制精度,抑制回路中的电子噪声:对滤波器来说,高Q值可以提高通带边缘信号频率相应陡度,提高频带的利用率,因此,高Q值微波介质材料在现代无线应用中必不可少。尽管传统的高Q值复合钙钛矿介质材料如Ba(Mg1/3Ta2/3)O3(BMT)和Ba(Zn1/3Ta2/3)O3(BZT)被广泛研究,但高的烧结温度(>1400℃)、苛刻的制备条件、昂贵的五氧化二钽价格限制了其在微波/毫米波领域的发展。
最近有研究表明,具有岩盐结构的锂基Li2TiO3微波介质材料在毫米波段具有优异的微波介电性能(εr~22.14、Qf~63,525GHz,τf~+20.3ppm/℃),原料相对便宜,制备工艺简单易行,但在(002)面易出现解理现象,表面存在微裂纹,严重影响了Li2TiO3的Qf值,导致其在实际应用中不能满足基站的要求,且烧结温度相对较高(~1300℃)。因此,提高Li2TiO3的Qf值,同时降低其烧结温度,成为目前亟待解决的问题。
发明内容
本发明的目的,是通过引入添加剂MgF2,改善Li2TiO3的解理现象,提高Li2TiO3微波介质材料的Qf值,同时氟化物具有促进烧结的作用,可降低Li2TiO3的烧结温度。最终,制备出中温烧结(<1200℃)的高Q值(>100,000GHz)Li2TiO3基微波介质材料。
本发明通过如下技术方案予以实现。
一种中温烧结高Q值微波介质材料,目标合成物表达式为Li2TiO3-x w.t.%MgF2,其中x=2~8。
上述中温烧结高Q值微波介质材料的制备方法,以MgF2、TiO2和Li2CO3为原料,采用固相法,具体实施步骤如下:
(1)将Li2CO3和TiO2按化学计量式Li2TiO3进行配料,将粉料放入聚酯球磨罐中,加入无水乙醇和氧化锆球后,球磨4~24小时;
(2)将步骤(1)球磨后的原料放入干燥箱中,于100~120℃烘干,然后过40目筛;
(3)将步骤(2)过筛后的粉料放入氧化铝坩埚内置于中温炉中,于700~900℃预烧,保温2~8小时,然后过40目筛;
(4)将步骤(3)过筛后的粉料外加质量百分比含量为2~8%的MgF2和质量百分比含量为0.7%的PVA粉末进行混合,放入聚酯球磨罐中,加入无水乙醇和氧化锆球后,球磨4~24小时进行造粒;
(5)将步骤(4)造粒后的的粉料放入干燥箱中,于100~120℃烘干4~6小时,然后过80目筛;
(6)将步骤(5)过筛后的粉料用粉末压片机以4~8MPa的压力制成生坯;
(7)将步骤(6)的生坯于1000℃-1200℃烧结,保温2~8小时,制成中温烧结高Q值Li2TiO3基微波介质材料
所述步骤(1)和(4)采用行星式球磨机进行球磨,球磨机转速为400转/分。
所述步骤(1)和(4)的原料与无水乙醇和氧化锆球的质量比为1:30:15。
所述步骤(6)的生坯直径为10mm,厚度为4~5mm。
所述步骤(7)的烧结温度为1120℃。
本发明以MgF2、TiO2和Li2CO3为原料制备新型中温烧结高Q值微波介质材料Li2TiO3-x w.t.%MgF2(x=2~8)。微波频段下,该材料实现了中温烧结(<1200℃),Qf值高达到123,730GHz~158,963GHz,本发明制备工艺简单,其制品具有广泛的应用前景。
具体实施方式
本发明以纯度大于99%的MgF2、TiO2和Li2CO3为初始原料,通过固相法制备微波介质材料。具体实施方案如下:
(1)将Li2CO3和TiO2按化学计量式Li2TiO3进行配料,将粉料放入聚酯球磨罐中,原料与无水乙醇和氧化锆球的质量比为1:30:15。,在行星式球磨机上球磨4~24小时,球磨转速为400/转分;
(2)将步骤(1)球磨后的原料分别放入干燥箱中,于100~120℃烘干5小时,然后过40目筛;
(3)将步骤(2)过筛后的粉料放入氧化铝坩埚内置于中温炉中,于700~090℃预烧,保温2~8小时,然后过40目筛;
(4)将步骤(3)过筛后的粉料外加质量百分比含量为2~8%的MgF2和质量百分比含量为0.7%的PVA粉末进行混合,放入聚酯球磨罐中,原料与无水乙醇和氧化锆球的质量比为1:30:15,在行星式球磨机上在行星式球磨机上球磨4~24小时进行造粒;
(5)将步骤(4)球磨后的原料分别放入干燥箱中,于100~120℃烘干4~6小时,然后过80目筛;
(6)将步骤(5)的粉料用粉末压片机以6MPa的压力制成生坯;
(7)将步骤(6)的生坯于1000℃~1200℃烧结,保温6小时;
(8)通过网络分析仪测试所得制品的微波介电性能。
本发明具体实施例的主要工艺参数及其微波介电性能详见表1。
表1

Claims (5)

1.一种中温烧结高Q值微波介质材料,目标合成物表达式为Li2TiO3-x w.t.%MgF2,其中x=2~8。
上述中温烧结高Q值微波介质材料的制备方法,以MgF2、TiO2和Li2CO3为原料,采用固相法,具体实施步骤如下:
(1)将Li2CO3和TiO2按化学计量式Li2TiO3进行配料,将粉料放入聚酯球磨罐中,加入无水乙醇和氧化锆球后,球磨4~24小时;
(2)将步骤(1)球磨后的原料放入干燥箱中,于100~120℃烘干,然后过40目筛;
(3)将步骤(2)过筛后的粉料放入氧化铝坩埚内置于中温炉中,于700~900℃预烧,保温2~8小时,然后过40目筛;
(4)将步骤(3)过筛后的粉料外加质量百分比含量为2~8%的MgF2和质量百分比含量为0.7%的PVA粉末进行混合,放入聚酯球磨罐中,加入无水乙醇和氧化锆球后,球磨4~24小时进行造粒;
(5)将步骤(4)造粒后的的粉料放入干燥箱中,于100~120℃烘干4~6小时,然后过80目筛;
(6)将步骤(5)过筛后的粉料用粉末压片机以4~8MPa的压力制成生坯;
(7)将步骤(6)的生坯于1000℃-1200℃烧结,保温2~8小时,制成中温烧结高Q值Li2TiO3基微波介质材料。
2.根据权利要求1所述的一种中温烧结高Q值微波介质材料,其特征在于,所述步骤(1)和(4)采用行星式球磨机进行球磨,球磨机转速为400转/分。
3.根据权利要求1所述的一种中温烧结高Q值微波介质材料,其特征在于,所述步骤(1)和(4)的原料与无水乙醇和氧化锆球的质量比为1:30:15。
4.根据权利要求1所述的一种中温烧结高Q值微波介质材料,其特征在于,所述步骤(6)的生坯直径为10mm,厚度为4~5mm。
5.根据权利要求1所述的一种中温烧结高Q值微波介质材料,其特征在于,所述步骤(7)的烧结温度为1120℃。
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