著者

橋本 建次

出版者

一般社団法人 資源・素材学会

雑誌

日本鉱業会誌 (ISSN:03694194)

巻号頁・発行日

vol.98, no.1134, pp.733-740, 1982-08-25 (Released:2011-07-13)

参考文献数

100

被引用文献数

2 1

---

A number of studies have recently been carried out in which the abrasive and erosive wear rate of the materials by the mineral grains was determined. In this paper the effects of various variables on these wear are summarized.M ain contents are as follows:1) Introduction: Difinition of wear, Classification of wear testing methods- three-body sliding friction between loose mineral grains and materials (flat-flat plate and flat-circle plate), two-body sliding friction between materials and minerals (fixed and loose abrasive), rolling and impacting between materials and loose mineral grains (ball or rod mills), rotating of materials in loose mineral grains, impacting of loose mineral grains against materials and impacting of materials against loose mineral grains-, Relations between different testing methods.2) Factors influencing abrasive and erosive wear: Knoop and micro Vickers hardness of minerals and materials, Correlationsbetween wear rate W and hardness ratio (material hardness Hm/mineral hardness Ha)-W∝(Hm/Ha) n-, Wear-resistant factors except hardness- Youngs modulas, tensile strength, fatigue strength, impact strength, etc.-, Effect of mineral grains size while the wear rate are proportional to the grain size, after the critical size (about 10-300 pm) it is almost constant-.3) Wear characteristics: Initial and steady wear processes-in steady wear the wear rate are proportional to sliding distance or impact time-, Influence of velocity V-W∝ Vn, where n value are 0-0.5 in two and three-body sliding friction testing methods, 0.8-1.3 in ball mill, 2-6.5 in testing methods of impacting of loosegrains against materials (metal: 2-3 and non-metal: 3-6.5)-, Influence of impact angle in erosive wear-the ductile materials exhibits maximum wear rate at low impact angle, but the brittle materials produces its maximum at high angle (for example, rubber: 0°, steel: 15-25°, castiron: 40-50°, glass: 90°).

著者

橋本 建次

出版者

公益社団法人 日本鋳造工学会

雑誌

鋳物 (ISSN:00214396)

巻号頁・発行日

vol.28, no.12, pp.899-904, 1956-12-25 (Released:2012-11-09)

参考文献数

12

---

An equation of the combined permeability of facing and backing sands is introduced and as its application, the relationship between permeability and surface roughness of castings was studied.   Main conclusions obtained were as follows :   1) The combined permeability of molding sands is calculated by the following equation             [Written in non-displayable characters.].       where H is height of each layer, K is permeability.   2) The above equation can be applied extensively to values of the permeability with a good accuracy.   3) The surface roughness of castings takes a minimum to a value of the combined permeability, which is changed by the mold surface or sand grain size, that is, with finer surface roughness of the mold the value declines to lower permeability. (Fig. 3) Therefore, in order to obtain fine surface roughness of castings, the combined permeability of facing and backing sands should be controlled properly according to mold surface roughness or sand grain size.