Rapid Preparation of Ceramic Mould for Medium-Sized Superalloy Castings with Magnesia-Phosphate-Bonded Bauxite-Mullite Investments
Phosphate-bonded investments have already been widely utilized in dental restoration and micro-casting of artistic products for its outstanding rapid setting and high strength. However, the rapid setting rate of investments slurry has up to now been a barrier to widespread use of such slurry in medium-sized ceramic mould preparing. This paper proposed a new process of rapid fabricating magnesia-phosphate-bonded investments ceramic mould for medium-sized superalloy castings utilizing bauxite and mullite as refractory aggregates. A series of experiments for magnesia-phosphate-bonded bauxite-mullite investments (MPBBMI) properties were conducted, including modifying the workable time of slurry by liquid (mL)/powder (g) (UP) ratio and adding boric acid as retard agent; sodium tri-polyphosphate (STP) as strengthening agent and bauxite (g)Imullite (g) (B/M) ratio for mechanical strength; Mechanical vibration was applied to improve initial setting time and fluidity when pouring investments slurry; then a intermediate size ceramic mould for superalloy castings was manufactured by means of this rapid preparing process with MPBBMI material. The results showed that the MPBBMI slurry exhibit proper initial setting time and excellent fluidity when UP ratio is 0.64, boric acid content is O. 88 wt％; the fired specimens made from MPBBMI material indicated enough compression strength to withstand impact force of molten metal when the B/M ratio is O. 89, STP content is 0.92 wt％; the experimental results confirmed feasibility of the proposed rapid fabricating process for medium-sized ceramic mould with MPBBMI material by appropriate measures.
medium-sized ceramic mould magnesia-phosphate-bonded bauxite-mullite investments superalloy castings initial setting time compressive strength
Li Tingzhong Luo Jirong Wu Shusen
State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and State Key Lab of Materials Processing and Die & Mould Technology,Huazhong University of Science and
国际会议
69th World Foundry Congress(第69届世界铸造会议 WFC 2010)
杭州
英文
992-995
2010-10-16（万方平台首次上网日期，不代表论文的发表时间）