【摘要】：鑄造粘結(jié)劑的研究重點(diǎn)已經(jīng)開(kāi)始向環(huán)境友好型方向發(fā)展,雖然樹(shù)脂砂得到廣泛應(yīng)用,在一定程度上提高了鑄件質(zhì)量和生產(chǎn)效率,但是在使用過(guò)程中會(huì)散發(fā)出刺激性氣味的有害氣體,污染了環(huán)境。而無(wú)機(jī)粘結(jié)劑砂具有發(fā)氣量低和無(wú)毒環(huán)保等特點(diǎn),是綠色粘結(jié)劑發(fā)展的方向。本文根據(jù)鑄造生產(chǎn)要求,研制出了一種無(wú)機(jī)鑄造粘結(jié)劑,通過(guò)溫芯盒制芯工藝固化,具有加入量低、強(qiáng)度高、潰散性好等特點(diǎn)。本文首先以水玻璃為主要成分,通過(guò)粉狀促硬劑+加熱+吹熱空氣的硬化工藝制芯。但普通的水玻璃砂芯強(qiáng)度低,潰散性差。因此,采用氫氧化鉀、焦磷酸鈉、B劑以及硅烷進(jìn)行復(fù)合改性,并以砂芯的抗拉強(qiáng)度和潰散性為考核指標(biāo),通過(guò)正交試驗(yàn)優(yōu)化了各組分的比例,即水玻璃:氫氧化鉀:B劑:焦磷酸鈉:硅烷=1000:45:8:4:2。然后,對(duì)促硬劑進(jìn)行復(fù)合,并通過(guò)正交試驗(yàn)對(duì)促硬劑成分配比進(jìn)行優(yōu)化,最終確定了最優(yōu)的促硬劑成分配比,即結(jié)晶二氧化硅:微硅粉:D劑:淀粉=15:10:1:1。然后對(duì)制芯工藝參數(shù)進(jìn)行了正交試驗(yàn)優(yōu)化,確定了最優(yōu)的制芯工藝,即芯盒溫度為175℃,熱空氣溫度為120℃,吹氣時(shí)間為40s。改性后的粘結(jié)劑粘度為78mPa·s,模數(shù)為2.33,密度為1.45g/cm3。在粘結(jié)劑加入量2%,促硬劑0.6%,活性劑0.5%的情況下,得到砂芯的熱強(qiáng)度為0.63MPa,常溫抗拉強(qiáng)度為2.60MPa,4h抗拉強(qiáng)度為2.64MPa,24h抗拉強(qiáng)度為2.54MPa。砂芯發(fā)氣量(850℃×3min)為8.5ml/g,高溫殘留強(qiáng)度(750℃×5min)為0MPa。最后,進(jìn)行制芯和澆注試驗(yàn),成功地制備出無(wú)機(jī)粘結(jié)劑砂芯,澆注出合格的鑄件,并進(jìn)行了總體工藝評(píng)價(jià)。
[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，

本文編號(hào)：2308393