1 / 36
文档名称:

合金铸造基础(有色金属铸造).ppt

格式:ppt   大小:151KB   页数:36页
下载后只包含 1 个 PPT 格式的文档,没有任何的图纸或源代码,查看文件列表

如果您已付费下载过本站文档,您可以点这里二次下载

分享

预览

合金铸造基础(有色金属铸造).ppt

上传人:今晚不太方便 2017/8/27 文件大小:151 KB

下载得到文件列表

合金铸造基础(有色金属铸造).ppt

文档介绍

文档介绍:BSE METAL CASATING ALLOYS
Base metal alloys contain no gold,
silver, platinum or palladium. The
two monly used base
metal alloys in dentistry are:
1. The nickel-chromium (Ni/Cr) alloys which monly used for crown and bridge casting.
The cobalt-chromium (Co/Cr) alloys which monly used for partial denture framework castings.
3. Titanium and titanium alloys.
Cobalt-Chromium Alloys (stellites)
Composition: These alloys
generally contain
35-65% cobalt.
20-35% chromiun.
0-30% nickel.
Trace quantities of other elements such as molybdenum, silicon, beryllium, boron and carbon.
Cobalt and nickel are hard, strong metals. The main purpose of the chromium is to further harden the alloy by solution hardening and also to impart corrosion resistance by the passivating effect
The minor elements are generally added
to improve casting and handling
characteristics and modify mechanical
properties.
Carbon affects the hardness, strength and
ductility of the alloys.
The exact concentration of carbon is one
of the major factors controlling alloy properties.
Nickel-Chromium Alloys
Composition:
70-80% nickel.
10-25% chromium.
Small quantities of other elements as described for the Co/Cr alloys.
Manipulation of base metal casting alloys
The fusion temperatures of the Ni/Cr and Co/Cr alloys vary position but are generally in the range 1200-1500ºC.
Investment moulds for base metal alloys must be capable of maintaining their integrity at the high casting temperatures used.
The density values of base metal alloys are approximately half those of the casting gold alloys.
The greatest expense involved in producing a Co/Cr dental casting is in the time required for trimming and polishing.
Base metal alloys, and particularly the Co/Cr type, are very hard and consequently difficult to polish.
Properties
The Co/Cr and Ni/Cr alloys are very hard materials.
Co/Cr and Ni/Cr alloys have very good
corrosion resistance by virtue of the
passivating effect.
Co/Cr al

最近更新

《文献资源开发部》 50页

一年级开学日常行为规范 30页

偶然误差累积的系统现象及其在摄影测量的应用.. 2页

保险机制在志愿者安全管理中的作用研究 2页

使用高效液相层析分析湿地松中酚类化合物的快.. 2页

低碳铝镇静钢中酸溶铝的快速预报和影响因素分.. 2页

低发泡聚酯聚氨酯热性能的研究(Ⅰ) 2页

优质精密螺纹零件滚压加工规律的研究 2页

煤炭铁路运输合同 6页

企业季度经济活动分析不能可有可无 2页

价值工程在190—12型柴油机结构改进上的应用 2页

港口与内河航运货物交接合同(示范文本GF--94-.. 6页

深圳钟点工合同样本——家政服务合同范本大全.. 6页

从木桶理论的发展史浅议管理研究方法 2页

从化石硅藻分析东江三角洲的沉积相 2页

消防设备维修保养服务合同 7页

海运合同关键要素探讨 6页

派遣人员劳务合同范本权威版 6页

沿街门面房租赁合同变更协议 5页

井下无线电话在基尔克矿的成功应用 2页

二茂二芳氧基钛、锆和铪衍生物的薄层色谱分析.. 2页

二氟氯甲烷-全氟丙烯二元系中压汽液平衡的研究.. 2页

乳化沥青土工布在尾矿坝基中的应用 2页

水库运维管理合同协议书范本 6页

主副螺纹型螺杆的改进与参数分析 2页

民生协议存款业务合同 6页

毕业生实习合同模板 5页

武汉医疗行业工作服订购合同样本 6页

中国风电装备制造业的空间格局及影响因素分析.. 2页

中国梧桐科植物花粉类型的研究 2页