| 摘要 |
<p>The invention provides a powder comprising at least 95% by number of fused grains, with the following chemical composition, as a percentage by weight based on the oxides, for a total of 100%: 0≰BaO≰40.8%; 0≰SrO≰31.8%; 27.2%≰Al2O3≰31.3%; 32%≰SiO2≰36.9%; other species≰1%; the quantity of at least one of the oxides BaO and SrO being more than 0.3%, the size of said grains being such that D5≧5μm and D95≰150μm.</p> |
