西南交《机械制造基础》在线作业一

adminhan

对于箱体零件上具有一定精度要求的孔系,通常在 () 机床上加工。
A:钻床
B:铣床
C:镗床
D:车床

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">适合制造齿轮刀具的材料是</span><span lang="EN-US" style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">(<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>)</span><span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">。</span>
A:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">碳素工具钢</span>
B:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">高速钢</span>
C:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">硬质合金</span>
D:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">陶瓷材料</span>

车削螺纹时,工件转动和刀具移动组成的机床运动是 ()。
A:简单成型形运动
B:复合成形运动
C:主运动
D:进给运动

滚齿机上不能加工 ()零件。
A:直齿圆柱齿轮
B:斜齿圆柱齿轮
C:内齿轮
D:蜗轮

卧式机床的主参数是指()。
A:最大的加工工件长度
B:床身的长度
C:主轴最大孔径
D:最大加工工件直径

在钻床上进行钻、扩、铰孔加工时,正确顺序是                。
A:钻、扩、铰
B:钻、铰、扩
C:铰、钻、扩
D:扩、铰、钻

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">引起锻件晶粒粗大的主要原因之一是</span><span lang="EN-US" style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">(<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>)</span><span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">。</span>
A:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">过热</span>
B:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">过烧</span>
C:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">变形抗力大</span>
D:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">塑性差</span>

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">在铸造生产中，流动性较好的铸造合金</span><span lang="EN-US" style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">(<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>)</span><span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">。</span>
A:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">结晶温度范围较小</span>
B:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">结晶温度范围较大</span>
C:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">结晶温度较高</span>
D:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">结晶温度较低</span>

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">金属材料在结晶过程中发生共晶转变就是指</span><span lang="EN-US" style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">(<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>)</span><span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">。</span>
A:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">从一种液相结晶出一种固相</span>
B:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">从一种液相结晶出两种不同的固相</span>
C:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">从一种固相转变成另一种固相</span>
D:<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">从一种固相转变成另两种不同的固相</span>

在齿轮切削加工中,通常下列()加工方法不属于展成法(范成法)加工。
A:插齿
B:磨齿
C:滚齿
D:铣齿

切削用量三要素是（）。
A:切削速度
B:切削深度
C:进给量
D:切削时间

刀具磨损的阶段分为几个过程？（）
A:初期磨损阶段
B:正常磨损阶段
C:扩散磨损阶段
D:剧烈磨损阶段

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">球铁</span><span lang="EN-US" style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">QT400</span><span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">&mdash;</span><span lang="EN-US" style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">18</span><span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">表示其材料的最低抗拉强度为4</span><span lang="EN-US" style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">00MPa</span><span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">。</span>
A:错误
B:正确

切削用量增加,功率消耗加大,切削热的生成加多,切削温度升高。(   )
A:错误
B:正确

切削温度是切削过程的一个重要物理量,主要影响刀具磨损和积屑瘤的产生,但对表面质量没有影响。(   )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">粗加工所用的定位基准称粗基准，精加工所用的定位基准为精基准。</span>
A:错误
B:正确

切屑瘤是在中等切速加工塑性材料条件下的一个重要物理现象。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">自激振动的振动频率接近于或低于工艺系统的低频振型的固有频率。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">拉削主要用于成批和大量生产中。</span>
A:错误
B:正确

切削热由切屑、工件、刀具和周围介质(如空气、切削液)传散出去。不同的加工方法其切削热传散的比例是相同。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">表面淬火件经淬火和低温回火后所获得的组织是回火托氏体。</span>
A:错误
B:正确

经过塑性变形后形成的切屑,其厚度hch通常都要小于工件上切削层的厚度hD,而切屑长度Lch通常大于切削层长度Lc。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">低碳钢的塑性太高，可以通过正火适当降低塑性，提高硬度。</span>
A:错误
B:正确

在切削塑性材料时,切削区温度最高点是在刀刃处。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">常见的预备热处理有退火和淬火等形式。</span>
A:错误
B:正确

切削温度的高低不仅取决于热源区产生热量的多少,而且还取决于散热条件的好坏。(   )
A:错误
B:正确

当切削塑性材料、切削速度v较高、切削厚度hD较大时易发生前刀面磨损。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">钻孔可用于粗加工又可用于精加工。</span>
A:错误
B:正确

切削时出现的积屑瘤、前刀面磨损等现象,都是第Ⅲ变形区的变形所造成的。(  )
A:错误
B:正确

凡影响切削变形、切削抗力及功率消耗的因素,都对生热有影响。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">液态金属凝固成固体的过程都称为结晶。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">自由锻用芯棒扩孔，实质是将坯料沿圆周方向镦粗。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">当铣削铸铁及锻件等带有黑皮的表面时，因刀齿首先接触黑皮，将加剧刀具的磨损，所以应采用顺铣法。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">尺寸链是指在机器装配或零件加过程中，由相互连接的尺寸形成封闭的尺寸组。</span>
A:错误
B:正确

在形成挤裂切屑的条件下,若减小刀具前角,减低切削速度,加大切削厚度,就可能得到崩碎切屑。(  )
A:错误
B:正确

进给抗力Ff是设计和校验机床进给机构强度的重要依据。(  )
A:错误
B:正确

第Ⅲ变形区的变形是造成已加工表面硬化和残余应力的主要原因。
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">在确定工艺尺寸链中的封闭环时，要根据零件的工艺方案紧紧抓住&ldquo;间接获得&rdquo;的尺寸这一要点。</span>
A:错误
B:正确

磨削时砂轮表面的微小磨粒切削刃的几何形状是不确定的,且通常有较大的前角和刃口楔角,以及较大的刃口钝圆半径。(   )
A:错误
B:正确

吃刀抗力可能引起工件的弯曲与振动,影响加工质量。(   )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">刃倾角主要影响刀头的强度和切屑流动的方向。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">工件在加工前，使其在机床上或夹具中获得正确而固定位置的过程称为安装。</span>
A:错误
B:正确

当切削脆性金属时,由于形成崩碎切屑,会出现后刀面磨损。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">工件在夹具中定位时，欠定位是绝对不允许的，过定位特殊情况下是可以存在的。</span>
A:错误
B:正确

切削用量中切削速度对刀具耐用度的影响最大,其次为切削深度,而进给量对刀具耐用度的影响最小。(  )
A:错误
B:正确

主切削力Fc是计算机床功率及设计夹具、刀具的主要依据。(  )
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">切削厚度对切屑变形没有影响。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">拉孔前工件须先制出预制孔。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">加工箱体零件时，应选择装配基准面为精基准。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">磨削内孔时，在工件孔径允许的条件下，应尽量选用大直径的砂轮。</span>
A:错误
B:正确