论文部分内容阅读
过去我厂生产的小孔厚壁铝青铜铸件常因内表面出现缩孔、气孔和氧化夹杂而报废。最典型的是牙轮钻机铝青铜活塞,牌号为ZQAL9-4,废品率曾高达60～70％。该件加工后的尺寸为外径φ160毫米,高80毫米,内径φ50毫米。开始我们采用铁型内孔铸死和下砂芯底注的办法生产该件,结果加工时发现内孔有较严重的缩孔、气孔和氧化夹杂。针对这种情况,我们又采用了下冷铁芯的办法。从试验的情况看,铸件的缩孔基本解决,但夹渣和气孔依然存在。根据生产过程中
In the past I produced a small hole thick-walled aluminum bronze castings often shrinkage due to internal surface porosity and oxidation inclusions scrapped. The most typical is the aluminum bronze piston cone drill, grade ZQAL9-4, scrap rate was as high as 60 to 70%. After processing the size of the outer diameter φ160 mm, height 80 mm, diameter φ50 mm. The beginning of our use of iron inner hole die casting and sand core under the note of the way to produce the pieces, the results found that the inner hole has more serious shrinkage, porosity and oxidation inclusions. In view of this situation, we have adopted the method of cold core. From the test situation, the casting of shrinkage basically solved, but the slag and pores still exist. According to the production process