低密度耐水PVA磨具的研制

Development of low density water-tolerant PVA abrasive tools

本文对聚乙烯醇(PVA)的缩醛化反应机理和影响因素进行了深入分析,提出了一种通过调整混合浆料的粘度避免沉积保证浇注制品均匀度的方法。采取化学发泡剂发泡,机械搅拌匀泡,控制PVA的缩醛化反应速率等技术措施,成功研制出含有丰富开孔结构微气孔的低密度磨具,并可以根据气孔的大小、多少,调整制品密度。确定了稳定的生产工艺和密度为0.4～0.8g/cm3的低密度耐水PVA磨具产品配方。针对不同的磨削对象,选用合适的磨料材质、粒度以及PVA磨具的硬度、密度,可广泛应用于不锈钢、有色金属和硬质合金的精磨、超精磨及镜面磨削,具有广阔的推广应用前景。

This research analyzed the acetalyzation reaction mechanism and influencing factors of polyvinyl alcohol（PVA） with formaldehyde. Through adjusting the viscosity of the serous mixture ,the precipitation was avoided and the homogeneity of the green pieces was guaranted. By taking technical measures, such as chemical foaming, mechanical mixing for uniform distribution of the bubbles and appropriate condensating reaction rate, we successfully produced PVA abrasive tools with abundant micro open bubbles and of different densities. The authors also worked out the manufacturing technique and formulae for low density （0.4- 0.8 g/ cm^3） water-tolerant PVA abrasive tools. With suitable kind and size of abrasive grains, appropriate hardness and density of abrasive tools for different polishing objects, these PVA abrasive tools can be widely used for polishing and mirror-finishing stainless steel, nonferrous metals and hard metal alloys.