【摘要】：高性能發(fā)動機的研發(fā),促進了陶瓷型芯的發(fā)展。氧化鋁陶瓷型芯具有很好的高溫性能,特別適合應用于精密定向鑄造中。但氧化鋁脫芯困難,對生產效率的提高非常不利。如何在保持型芯其他良好性能的前提下提高脫芯性能至關重要。本文將主要從基體材料的選擇、基體材料的粒度配合、礦化劑的添加以及終燒制度的確定等方面進行研究,確定最佳配方和工藝。相應測定的性能主要有室溫抗彎強度、高溫撓度、開氣孔率,體積密度、吸水率、收縮率、燒損率和脫芯效率。陶瓷型芯綜合性能的均衡優(yōu)化非常關鍵,在基體材料的選擇試驗中,隨莫來石含量的增加,各個性能產生很大變化,對比所有試樣的各項實驗結果,當莫來石含量為15%時綜合性能相對較好。在此配方的基礎上進行了基體材料粒度配合對性能影響的研究,經過粒度配合后的型芯性能得到進一步改善。在保持型芯其他良好性能的前提下為了提高脫芯性能,又分別對作為礦化劑的莫來石和石英粉進行了實驗探究,主要分析礦化劑添加量的梯度變化對性能的影響,從中得出(終燒溫度為1350℃)石英粉含量為10%時的L-4型配方型芯綜合性能最佳:抗彎強度為26.45MPa;撓度值為1.37mm;收縮率為0.58%;開氣孔率為47.78%;經過180min濃度為60%沸騰強堿液處理,損失的質量百分數(shù)達到96.21%。在提高脫芯性能的同時,其他各項性能也得到了很好的保持。在最佳配方L-4的基礎上對其終燒溫度進行了研究。對比1350℃、1450℃和1550℃三種不同最終保溫溫度所得型芯的各項性能,最終保溫溫度在1350℃時L-4型配方型芯綜合性能最佳。對型芯L-4進行高溫強化處理后,在1550℃下保溫30min測定其撓度值,其數(shù)值下降為0.23mm,高溫撓度得到改善。
[Abstract]:The development of high performance engine promotes the development of ceramic core. Alumina ceramic core has good high temperature performance, especially suitable for precision directional casting. However, it is difficult to core alumina, which is unfavorable to the improvement of production efficiency. It is very important to improve the core removal performance on the premise of other good performance of retaining core. In this paper, the selection of matrix material, the particle size matching of matrix material, the addition of mineralizer and the determination of final firing system are studied to determine the optimum formulation and process. The main properties measured include room temperature bending strength, high temperature deflection, open porosity, bulk density, water absorption, shrinkage, burn loss and core removal efficiency. It is very important to balance and optimize the comprehensive properties of ceramic core. In the selection test of matrix material, with the increase of mullite content, the properties vary greatly. When mullite content is 15, the comprehensive performance is relatively good. On the basis of this formula, the effect of particle size matching on the properties of matrix materials was studied, and the core properties were further improved after particle size matching. In order to improve the core demineralization performance, mullite and quartz powder, which are mineralizers, were studied respectively in order to improve the core performance. The influence of the gradients of mineralizers on the properties was analyzed. The L-4 formula core with 10 quartz powder content (final firing temperature 1350 鈩，

本文編號：2148842