hard spot meaning in Chinese

(牌价高的)特别稳定的股票
应力集中点
硬点

The hard spots and nonmetallic inclusion in aluminum alloy die casting are studied through measuring chemical composition and micro - hardness . the source of these inclusion is analyzed and prevention measures are suggested
研究了铝合金压铸件中的硬质点及其中的非金属夹杂物，测定了它们的化学成分和显微硬度，并分析了它们的来源，提出了防止的措施。
Specimen of typical hard spot in aluminum alloy die casting is analyzed . the cause for formation of hard spots is discussed and effective methods to prevent hard spot are proposed
切削加工铝合金压铸件时，经常会碰到硬质点打刀现象，严重影响刀具寿命和加工质量，针对这个问题，对压铸件中出现的典型硬质点取样分析，探讨了硬质点的形成原因，并提出了有效的解决措施。