例句與造句

1. Abstract : the structure and the properties of the grinding ball made of the composite cast iron have been researched in this paper . the result indicates that added trace boron and a proper quantity copper to this kind of composite cast iron can increase its quench - hardening ability , and raise its hardness and impact toughness
   文摘:研究了一種復合鑄鐵磨球的組織和性能，結果表明，化學成分和淬火工藝對這種復合鑄鐵磨球的組織和性能有很大影響，微量的硼和適量的銅可以明顯地提高磨球的淬透性，經(jīng)過余熱淬火得到貝氏體或馬氏體基體組織，從而提高磨球的硬度和沖擊韌性。
2. It's difficult to find composite casting in a sentence. 用composite casting造句挺難的