温芯盒无机粘结剂制芯材料及工艺的研究
发布时间：2018-11-03 17:01
【摘要】：铸造粘结剂的研究重点已经开始向环境友好型方向发展,虽然树脂砂得到广泛应用,在一定程度上提高了铸件质量和生产效率,但是在使用过程中会散发出刺激性气味的有害气体,污染了环境。而无机粘结剂砂具有发气量低和无毒环保等特点,是绿色粘结剂发展的方向。本文根据铸造生产要求,研制出了一种无机铸造粘结剂,通过温芯盒制芯工艺固化,具有加入量低、强度高、溃散性好等特点。本文首先以水玻璃为主要成分,通过粉状促硬剂+加热+吹热空气的硬化工艺制芯。但普通的水玻璃砂芯强度低,溃散性差。因此,采用氢氧化钾、焦磷酸钠、B剂以及硅烷进行复合改性,并以砂芯的抗拉强度和溃散性为考核指标,通过正交试验优化了各组分的比例,即水玻璃:氢氧化钾:B剂:焦磷酸钠:硅烷=1000:45:8:4:2。然后,对促硬剂进行复合,并通过正交试验对促硬剂成分配比进行优化,最终确定了最优的促硬剂成分配比,即结晶二氧化硅:微硅粉:D剂:淀粉=15:10:1:1。然后对制芯工艺参数进行了正交试验优化,确定了最优的制芯工艺,即芯盒温度为175℃,热空气温度为120℃,吹气时间为40s。改性后的粘结剂粘度为78mPa·s,模数为2.33,密度为1.45g/cm3。在粘结剂加入量2%,促硬剂0.6%,活性剂0.5%的情况下,得到砂芯的热强度为0.63MPa,常温抗拉强度为2.60MPa,4h抗拉强度为2.64MPa,24h抗拉强度为2.54MPa。砂芯发气量(850℃×3min)为8.5ml/g,高温残留强度(750℃×5min)为0MPa。最后,进行制芯和浇注试验,成功地制备出无机粘结剂砂芯,浇注出合格的铸件,并进行了总体工艺评价。
[Abstract]:The research focus of casting binder has begun to develop towards environment-friendly, although resin sand has been widely used to improve casting quality and production efficiency to a certain extent. However, the use of harmful gases that emit irritating odors pollutes the environment. Inorganic binder sand is the development direction of green binder because of its low gas generation and non-toxic environmental protection. According to the requirement of foundry production, a kind of inorganic casting binder has been developed in this paper, which is solidified by the core-making process of warm core box and has the characteristics of low addition, high strength, good collapsibility and so on. In this paper, water glass is first used as the main component, and the core is made by the hardening technology of powdery hardening agent heated by blowing hot air. But the strength of common sodium silicate sand core is low and the collapsibility is poor. Therefore, the composite modification of potassium hydroxide, sodium pyrophosphate, agent B and silane was carried out, and the tensile strength and collapsibility of the sand core were taken as the evaluation index, and the proportion of each component was optimized by orthogonal test. Sodium silicate: potassium hydroxide: agent B: sodium pyrophosphate: silane = 1000: 45: 8: 4: 2. Then, the compound of hardener was carried out, and the optimum ratio of hardener was determined by orthogonal experiment, that is, crystalline silica: microsilica: D-agent: starch = 15: 10: 1: 1: 1. Then the parameters of core-making were optimized by orthogonal test, and the optimum core-making process was determined. The core box temperature was 175 鈩，
本文编号：2308393
[Abstract]:The research focus of casting binder has begun to develop towards environment-friendly, although resin sand has been widely used to improve casting quality and production efficiency to a certain extent. However, the use of harmful gases that emit irritating odors pollutes the environment. Inorganic binder sand is the development direction of green binder because of its low gas generation and non-toxic environmental protection. According to the requirement of foundry production, a kind of inorganic casting binder has been developed in this paper, which is solidified by the core-making process of warm core box and has the characteristics of low addition, high strength, good collapsibility and so on. In this paper, water glass is first used as the main component, and the core is made by the hardening technology of powdery hardening agent heated by blowing hot air. But the strength of common sodium silicate sand core is low and the collapsibility is poor. Therefore, the composite modification of potassium hydroxide, sodium pyrophosphate, agent B and silane was carried out, and the tensile strength and collapsibility of the sand core were taken as the evaluation index, and the proportion of each component was optimized by orthogonal test. Sodium silicate: potassium hydroxide: agent B: sodium pyrophosphate: silane = 1000: 45: 8: 4: 2. Then, the compound of hardener was carried out, and the optimum ratio of hardener was determined by orthogonal experiment, that is, crystalline silica: microsilica: D-agent: starch = 15: 10: 1: 1: 1. Then the parameters of core-making were optimized by orthogonal test, and the optimum core-making process was determined. The core box temperature was 175 鈩，
本文编号：2308393
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