キャビテーション壊食に関する研究

第5報 : プラスチックスおよび金属材料の耐壊食特性

抄録

Erosion test due to impingement of a cavitating jet was performed using plastic and metal specimens. The experimental conditions were specified by the following : supply pressure of 9.9 MPa, cavitation coefficient of 0.02, stand-off distance of 25.0 mm and test fluid being tap water. The specimens tested were seven kinds of metals and six kinds of plastics. The metal specimens were made from austenitic (SUS316 in JIS) and martensitic (SUS403, SUS440B) types of stainless steel, precipitation hardening stainless steel (SUS630-H900, SUS630-H1075), stellite (No. 6) and aluminum alloy (A5056BD). The plastic specimens were made from polytetrafluoroethylene matrix composite (pure PTFE, PTFE reinforced with 60% bronze, PTFE reinforced with both 5% graphite and 20% glass fiber), polyetheretherketone (PEEK-450FC30, PEEK-EXL6) and polyimide resin (AURUM-JCL4030). These specimens made from aluminum alloy, PTFE, PEEK, stainless steels and stellite were eroded in that order. Erosion resistance was evaluated by the indices composed of their hardness, elastic modulus and mechanical strength. A modified ultimate resilience was proposed as a normalized erosion index and it showed good correlation.